Hybrid maize 35D28

ABSTRACT

According to the invention, there is provided a hybrid maize plant, designated as 35D28, produced by crossing two Pioneer Hi-Bred International, Inc. proprietary inbred maize lines. This invention relates to the hybrid seed 35D28, the hybrid plant produced from the seed, and variants, mutants, and trivial modifications of hybrid 35D28. This invention also relates to methods for producing a maize plant containing in its genetic material one or more transgenes and to the transgenic maize plants produced by those methods. This invention further relates to methods for producing maize lines derived from hybrid maize line 35D28 and to the maize lines derived by the use of those methods.

FIELD OF THE INVENTION

[0001] This invention relates generally to the field of maize breeding,specifically relating to hybrid maize designated 35D28.

BACKGROUND OF THE INVENTION Plant Breeding

[0002] The goal of plant breeding is to combine in a single variety orhybrid various desirable traits. For field crops, these traits mayinclude resistance to diseases and insects, tolerance to heat anddrought, reducing the time to crop maturity, greater yield, and betteragronomic quality. With mechanical harvesting of many crops, uniformityof plant characteristics such as germination and stand establishment,growth rate, maturity, and plant and ear height is important.

[0003] Field crops are bred through techniques that take advantage ofthe plant's method of pollination. A plant is self-pollinated if pollenfrom one flower is transferred to the same or another flower of the sameplant. A plant is sib pollinated when individuals within the same familyor line are used for pollination. A plant is cross-pollinated if thepollen comes from a flower on a different plant from a different familyor line. The term “cross pollination” and “out-cross” as used herein donot include self pollination or sib pollination.

[0004] Plants that have been self-pollinated and selected for type formany generations become homozygous at almost all gene loci and produce auniform population of true breeding progeny. A cross between twodifferent homozygous lines produces a uniform population of hybridplants that may be heterozygous for many gene loci. A cross of twoplants each heterozygous at a number of gene loci will produce apopulation of heterogeneous plants that differ genetically and will notbe uniform.

[0005] Maize (Zea mays L.), often referred to as corn in the UnitedStates, can be bred by both self-pollination and cross-pollinationtechniques. Maize has separate male and female flowers on the sameplant, located on the tassel and the ear, respectively. Naturalpollination occurs in maize when wind blows pollen from the tassels tothe silks that protrude from the tops of the ears.

[0006] The development of a hybrid maize variety in a maize plantbreeding program involves three steps: (1) the selection of plants fromvarious germplasm pools for initial breeding crosses; (2) the selfing ofthe selected plants from the breeding crosses for several generations toproduce a series of inbred lines, which, individually breed true and arehighly uniform; and (3) crossing a selected inbred line with anunrelated inbred line to produce the hybrid progeny (F1). After asufficient amount of inbreeding successive filial generations willmerely serve to increase seed of the developed inbred. Preferably, aninbred line should comprise homozygous alleles at about 95% or more ofits loci.

[0007] During the inbreeding process in maize, the vigor of the linesdecreases. Vigor is restored when two different inbred lines are crossedto produce the hybrid progeny (F1). An important consequence of thehomozygosity and homogeneity of the inbred lines is that the hybridcreated by crossing a defined pair of inbreds will always be the same.Once the inbreds that create a superior hybrid have been identified, acontinual supply of the hybrid seed can be produced using these inbredparents and the hybrid corn plants can then be generated from thishybrid seed supply.

[0008] Large scale commercial maize hybrid production, as it ispracticed today, requires the use of some form of male sterility systemwhich controls or inactivates male fertility. A reliable method ofcontrolling male fertility in plants also offers the opportunity forimproved plant breeding. This is especially true for development ofmaize hybrids, which relies upon some sort of male sterility system.There are several ways in which a maize plant can be manipulated so thatis male sterile. These include use of manual or mechanical emasculation(or detasseling), cytoplasmic genetic male sterility, nuclear geneticmale sterility, gametocides and the like.

[0009] Hybrid maize seed is often produced by a male sterility systemincorporating manual or mechanical detasseling. Alternate strips of twoinbred varieties of maize are planted in a field, and the pollen-bearingtassels are removed from one of the inbreds (female) prior to pollenshed. Providing that there is sufficient isolation from sources offoreign maize pollen, the ears of the detasseled inbred will befertilized only from the other inbred (male), and the resulting seed istherefore hybrid and will form hybrid plants.

[0010] The laborious detasseling process can be avoided by usingcytoplasmic male-sterile (CMS) inbreds. Plants of a CMS inbred are malesterile as a result of factors resulting from the cytoplasmic, asopposed to the nuclear, genome. Thus, this characteristic is inheritedexclusively through the female parent in maize plants, since only thefemale provides cytoplasm to the fertilized seed. CMS plants arefertilized with pollen from another inbred that is not male-sterile.Pollen from the second inbred may or may not contribute genes that makethe hybrid plants male-fertile. The same hybrid seed, a portion producedfrom detasseled fertile maize and a portion produced using the CMSsystem can be blended to insure that adequate pollen loads are availablefor fertilization when the hybrid plants are grown.

[0011] There are several methods of conferring genetic male sterilityavailable, such as multiple mutant genes at separate locations withinthe genome that confer male sterility, as disclosed in U.S. Pat. Nos.4,654,465 and 4,727,219 to Brar et al. and chromosomal translocations asdescribed by Patterson in U.S. Pat. Nos. 3,861,709 and 3,710,511. Theseand all patents referred to are incorporated by reference. In additionto these methods, Albertsen et al., of Pioneer Hi-Bred, U.S. Pat. No.5,432,068, have developed a system of nuclear male sterility whichincludes: identifying a gene which is critical to male fertility;silencing this native gene which is critical to male fertility; removingthe native promoter from the essential male fertility gene and replacingit with an inducible promoter; inserting this genetically engineeredgene back into the plant; and thus creating a plant that is male sterilebecause the inducible promoter is not “on” resulting in the malefertility gene not being transcribed. Fertility is restored by inducing,or turning “on”, the promoter, which in turn allows the gene thatconfers male fertility to be transcribed.

[0012] There are many other methods of conferring genetic male sterilityin the art, each with its own benefits and drawbacks. These methods usea variety of approaches such as delivering into the plant a geneencoding a cytotoxic substance associated with a male tissue specificpromoter or an antisense system in which a gene critical to fertility isidentified and an antisense to that gene is inserted in the plant (see:Fabinjanski, et al. EPO 89/3010153.8 Publication No. 329,308 and PCTApplication PCT/CA90/00037 published as WO 90/08828).

[0013] Another system useful in controlling male sterility makes use ofgametocides. Gametocides are not a genetic system, but rather a topicalapplication of chemicals. These chemicals affect cells that are criticalto male fertility. The application of these chemicals affects fertilityin the plants only for the growing season in which the gametocide isapplied (see Carlson, Glenn R., U.S. Pat. No. 4,936,904). Application ofthe gametocide, timing of the application and genotype specificity oftenlimit the usefulness of the approach and it is not appropriate in allsituations.

[0014] The use of male sterile inbreds is but one factor in theproduction of maize hybrids. The development of maize hybrids in a maizeplant breeding program requires, in general, the development ofhomozygous inbred lines, the crossing of these lines, and the evaluationof the crosses. Maize plant breeding programs combine the geneticbackgrounds from two or more inbred lines or various other germplasmsources into breeding populations from which new inbred lines aredeveloped by selfing and selection of desired phenotypes. Hybrids alsocan be used as a source of plant breeding material or as sourcepopulations from which to develop or derive new maize lines. Plantbreeding techniques known in the art and used in a maize plant breedingprogram include, but are not limited to, recurrent selection,backcrossing, double haploids, pedigree breeding, restriction fragmentlength polymorphism enhanced selection, genetic marker enhancedselection, and transformation. Often a combination of these techniquesare used. The inbred lines derived from hybrids can be developed usingplant breeding techniques as described above. New inbreds are crossedwith other inbred lines and the hybrids from these crosses are evaluatedto determine which of those have commercial potential.

[0015] Backcrossing can be used to improve inbred lines and a hybridwhich is made using those inbreds. Backcrossing can be used to transfera specific desirable trait from one line, the donor parent, to an inbredcalled the recurrent parent which has overall good agronomiccharacteristics yet that lacks the desirable trait. This transfer of thedesirable trait into an inbred with overall good agronomiccharacteristics can be accomplished by first crossing a recurrent parentto a donor parent (non-recurrent parent). The progeny of this cross isthen mated back to the recurrent parent followed by selection in theresultant progeny for the desired trait to be transferred from thenon-recurrent parent. Typically after four or more backcross generationswith selection for the desired trait, the progeny will containessentially all genes of the recurrent parent except for the genescontrolling the desired trait. But the number of backcross generationscan be less if molecular markers are used during the selection or elitegermplasm is used as the donor parent. The last backcross generation isthen selfed to give pure breeding progeny for the gene(s) beingtransferred.

[0016] Backcrossing can also be used in conjunction with pedigreebreeding to develop new inbred lines. For example, an F1 can be createdthat is backcrossed to one of its parent lines to create a BC1. Progenyare selfed and selected so that the newly developed inbred has many ofthe attributes of the recurrent parent and some of the desiredattributes of the non-recurrent parent.

[0017] Recurrent selection is a method used in a plant breeding programto improve a population of plants. The method entails individual plantscross pollinating with each other to form progeny which are then grown.The superior progeny are then selected by any number of methods, whichinclude individual plant, half sib progeny, full sib progeny, selfedprogeny and topcrossing. The selected progeny are cross pollinated witheach other to form progeny for another population. This population isplanted and again superior plants are selected to cross pollinate witheach other. Recurrent selection is a cyclical process and therefore canbe repeated as many times as desired. The objective of recurrentselection is to improve the traits of a population. The improvedpopulation can then be used as a source of breeding material to obtaininbred lines to be used in hybrids or used as parents for a syntheticcultivar. A synthetic cultivar is the resultant progeny formed by theintercrossing of several selected inbreds. Mass selection is a usefultechnique when used in conjunction with molecular marker enhancedselection.

[0018] Molecular markers including techniques such as IsozymeElectrophoresis, Restriction Fragment Length Polymorphisms (RFLPs),Randomly Amplified Polymorphic DNAs (RAPDs), Arbitrarily PrimedPolymerase Chain Reaction (AP-PCR), DNA Amplification Fingerprinting(DAF), Sequence Characterized Amplified Regions (SCARs), AmplifiedFragment Length Polymorphisms (AFLPs), Single Nucleotide Polymorphisms(SNPs) and Simple Sequence Repeats (SSRs) may be used in plant breedingmethods utilizing 35D28. One use of molecular markers is QuantitativeTrait Loci (QTL) mapping. QTL mapping is the use of markers, which areclosely linked to alleles that have measurable effects on a quantitativetrait. Selection in the breeding process is based upon the accumulationof markers linked to the positive effecting alleles and/or theelimination of the markers linked to the negative effecting alleles fromthe plant's genome.

[0019] Molecular markers can also be used during the breeding processfor the selection of qualitative traits. For example, markers closelylinked to alleles or markers containing sequences within the actualalleles of interest can be used to select plants that contain thealleles of interest during a backcrossing breeding program. The markerscan also be used to select for the genome of the recurrent parent andagainst the markers of the donor parent. Using this procedure canminimize the amount of genome from the donor parent that remains in theselected plants. It can also be used to reduce the number of crossesback to the recurrent parent needed in a backcrossing program. The useof molecular markers in the selection process is often called GeneticMarker Enhanced Selection.

[0020] The production of double haploids can also be used for thedevelopment of inbreds in a breeding program. Double haploids areproduced by the doubling of a set of chromosomes (1N) from aheterozygous plant to produce a completely homozygous individual. Forexample, see Wan et al., “Efficient Production of Doubled Haploid PlantsThrough Colchicine Treatment of Anther-Derived Maize Callus”,Theoretical and Applied Genetics, 77:889-892, 1989 and U.S. Application2003/0005479. This can be advantageous because the process omits thegenerations of selfing needed to obtain a homozygous plant from aheterozygous source.

[0021] Hybrid seed production requires elimination or inactivation ofpollen produced by the female parent. Incomplete removal or inactivationof the pollen provides the potential for self-pollination. Thisinadvertently self-pollinated seed may be unintentionally harvested andpackaged with hybrid seed. Also, because the male parent is grown nextto the female parent in the field there is the very low probability thatthe male selfed seed could be unintentionally harvested and packagedwith the hybrid seed. Once the seed from the hybrid bag is planted, itis possible to identify and select these self-pollinated plants. Theseself-pollinated plants will be genetically equivalent to one of theinbred lines used to produce the hybrid. Though the possibility ofinbreds being included in hybrid seed bags exists, the occurrence isvery low because much care is taken to avoid such inclusions. It isworth noting that hybrid seed is sold to growers for the production ofgrain and forage and not for breeding or seed production.

[0022] By an individual skilled in plant breeding, these inbred plantsunintentionally included in commercial hybrid seed can be identified andselected due to their decreased vigor when compared to the hybrid.Inbreds are identified by their less vigorous appearance for vegetativeand/or reproductive characteristics, including shorter plant height,small ear size, ear and kernel shape, cob color, or othercharacteristics.

[0023] Identification of these self-pollinated lines can also beaccomplished through molecular marker analyses. See, “The Identificationof Female Selfs in Hybrid Maize: A Comparison Using Electrophoresis andMorphology”, Smith, J. S. C. and Wych, R. D., Seed Science andTechnology 14, pp. 1-8 (1995), the disclosure of which is expresslyincorporated herein by reference. Through these technologies, thehomozygosity of the self pollinated line can be verified by analyzingallelic composition at various loci along the genome. Those methodsallow for rapid identification of the invention disclosed herein. Seealso, “Identification of A typical Plants in Hybrid Maize Seed byPostcontrol and Electrophoresis” Sarca, V. et al., Probleme de GeneticaTeoritica si Aplicata Vol. 20 (1) pp. 29-42.

[0024] Another form of commercial hybrid production involves the use ofa mixture of male sterile hybrid seed and male pollinator seed. Whenplanted, the resulting male sterile hybrid plants are pollinated by thepollinator plants. This method is primarily used to produce grain withenhanced quality grain traits, such as high oil, because desired qualitygrain traits expressed in the pollinator will also be expressed in thegrain produced on the male sterile hybrid plant. In this method thedesired quality grain trait does not have to be incorporated by lengthyprocedures such as recurrent backcross selection into an inbred parentline. One use of this method is described in U.S. Pat. Nos. 5,704,160and 5,706,603.

[0025] There are many important factors to be considered in the art ofplant breeding, such as the ability to recognize important morphologicaland physiological characteristics, the ability to design evaluationtechniques for genotypic and phenotypic traits of interest, and theability to search out and exploit the genes for the desired traits innew or improved combinations.

[0026] The objective of commercial maize hybrid line developmentresulting from a maize plant breeding program is to develop new inbredlines to produce hybrids that combine to produce high grain yields andsuperior agronomic performance. One of the primary traits breeders seekis yield. However, many other major agronomic traits are of importancein hybrid combination and have an impact on yield or otherwise providesuperior performance in hybrid combinations. Such traits include percentgrain moisture at harvest, relative maturity, resistance to stalkbreakage, resistance to root lodging, grain quality, and disease andinsect resistance. In addition, the lines per se must have acceptableperformance for parental traits such as seed yields, kernel sizes,pollen production, all of which affect ability to provide parental linesin sufficient quantity and quality for hybridization. These traits havebeen shown to be under genetic control and many if not all of the traitsare affected by multiple genes.

[0027] A breeder uses various methods to help determine which plantsshould be selected from the segregating populations and ultimately whichinbred lines will be used to develop hybrids for commercialization. Inaddition to the knowledge of the germplasm and other skills the breederuses, a part of the selection process is dependent on experimentaldesign coupled with the use of statistical analysis. Experimental designand statistical analysis are used to help determine which plants, whichfamily of plants, and finally which inbred lines and hybrid combinationsare significantly better or different for one or more traits ofinterest. Experimental design methods are used to assess error so thatdifferences between two inbred lines or two hybrid lines can be moreaccurately determined. Statistical analysis includes the calculation ofmean values, determination of the statistical significance of thesources of variation, and the calculation of the appropriate variancecomponents. Either a five or one percent significance level iscustomarily used to determine whether a difference that occurs for agiven trait is real or due to the environment or experimental error. Oneof ordinary skill in the art of plant breeding would know how toevaluate the traits of two plant varieties to determine if there is nosignificant difference between the two traits expressed by thosevarieties. For example, see Fehr, Walt, Principles of CultivarDevelopment, pp. 261-286 (1987) which is incorporated herein byreference. Mean trait values may be used to determine whether traitdifferences are significant, and preferably the traits are measured onplants grown under the same environmental conditions.

[0028] Combining ability of a line, as well as the performance of theline per se, is a factor in the selection of improved maize inbreds.Combining ability refers to a line's contribution as a parent whencrossed with other lines to form hybrids. The hybrids formed for thepurpose of selecting superior lines are designated test crosses. One wayof measuring combining ability is by using breeding values. Breedingvalues are based in part on the overall mean of a number of testcrosses. This mean is then adjusted to remove environmental effects andit is adjusted for known genetic relationships among the lines.

[0029] Once such a line is developed its value to society is substantialsince it is important to advance the germplasm base as a whole in orderto maintain or improve traits such as yield, disease resistance, pestresistance and plant performance in extreme weather conditions.

SUMMARY OF THE INVENTION

[0030] According to the invention, there is provided a hybrid maizeplant, and its parts designated as 35D28, produced by crossing twoPioneer Hi-Bred International, Inc. proprietary inbred maize linesGE568076 and GE760370. These lines, deposited with the American TypeCulture Collection, (ATCC), Manassas, Va. 20110, have Accession Number______ for GE568076 and Accession Number ______ for GE760370. Thisinvention thus relates to the hybrid seed 35D28, the hybrid plant andits parts produced from the seed, and variants, mutants and trivialmodifications of hybrid maize 35D28. This invention also relates tomethods for producing a maize plant containing in its genetic materialone or more transgenes and to the transgenic maize plants and theirparts produced by those methods. This invention further relates tomethods for producing maize lines derived from hybrid maize 35D28 and tothe maize lines derived by the use of those methods. This hybrid maizeplant is characterized by excellent grain yield, rapid grain moisturedrydown and vigorous early plant growth.

[0031] Definitions

[0032] Certain definitions used in the specification are provided below.In order to provide a clear and consistent understanding of thespecification and claims, including the scope to be given such terms,the following definitions are provided. NOTE: ABS is in absolute termsand % MN is percent of the mean for the experiments in which the inbredor hybrid was grown. PCT designates that the trait is calculated as apercentage. % NOT designates the percentage of plants that did notexhibit trait. For example, STKLDG % NOT is the percentage of plants ina plot that were not stalk lodged. These designators will follow thedescriptors to denote how the values are to be interpreted. Below arethe descriptors used in the data tables included herein.

[0033] ABTSTK=ARTIFICIAL BRITTLE STALK. A count of the number of“snapped” plants per plot following machine snapping. A snapped planthas its stalk completely snapped at a node between the base of the plantand the node above the ear. Expressed as percent of plants that did notsnap.

[0034] ADF=PERCENT ACID DETERGENT FIBER. The percent of dry matter thatis acid detergent fiber in chopped whole plant forage.

[0035] ALLELE. Any of one or more alternative forms of a geneticsequence. In a diploid cell or organism, the two alleles of a givensequence typically occupy corresponding loci on a pair of homologouschromosomes.

[0036] ANTROT=ANTHRACNOSE STALK ROT (Colletotrichum graminicola). A 1 to9 visual rating indicating the resistance to Anthracnose Stalk Rot. Ahigher score indicates a higher resistance.

[0037] BACKCROSSING. Process in which a breeder crosses a hybrid progenyline back to one of the parental genotypes one or more times.

[0038] BARPLT=BARREN PLANTS. The percent of plants per plot that werenot barren (lack ears).

[0039] BREEDING. The genetic manipulation of living organisms.

[0040] BREEDING CROSS. A cross to introduce new genetic material into aplant for the development of a new variety. For example, one could crossplant A with plant B, wherein plant B would be genetically differentfrom plant A. After the breeding cross, the resulting F1 plants couldthen be selfed or sibbed for one, two, three or more times (F1, F2, F3,etc.) until a new inbred variety is developed. For clarification, suchnew inbred varieties would be within a pedigree distance of one breedingcross of plants A and B. The process described above would be referredto as one breeding cycle.

[0041] BRTSTK=BRITTLE STALKS. This is a measure of the stalk breakagenear the time of pollination, and is an indication of whether a hybridor inbred would snap or break near the time of flowering under severewinds. Data are presented as percentage of plants that did not snap.

[0042] CELL. Cell as used herein includes a plant cell, whetherisolated, in tissue culture or incorporated in a plant or plant part.

[0043] CLDTST=COLD TEST. The percent of plants that germinate under coldtest conditions.

[0044] CLN=CORN LETHAL NECROSIS. Synergistic interaction of maizechlorotic mottle virus (MCMV) in combination with either maize dwarfmosaic virus (MDMV-A or MDMV-B) or wheat streak mosaic virus (WSMV). A 1to 9 visual rating indicating the resistance to Corn Lethal Necrosis. Ahigher score indicates a higher resistance.

[0045] COMRST=COMMON RUST (Puccinia sorghi). A 1 to 9 visual ratingindicating the resistance to Common Rust. A higher score indicates ahigher resistance.

[0046] CP=PERCENT OF CRUDE PROTEIN. The percent of dry matter that iscrude protein in chopped whole plant forage.

[0047] CROSS POLLINATION. A plant is cross pollinated if the pollencomes from a flower on a different plant from a different family orline. Cross pollination excludes sib and self pollination.

[0048] CROSS. As used herein, the term “cross” or “crossing” can referto a simple X by Y cross, or the process of backcrossing, depending onthe context.

[0049] D/D=DRYDOWN. This represents the relative rate at which a hybridwill reach acceptable harvest moisture compared to other hybrids on a 1to 9 rating scale. A high score indicates a hybrid that dries relativelyfast while a low score indicates a hybrid that dries slowly.

[0050] DIPERS=DIPLODIA EAR MOLD SCORES (Diplodia maydis and Diplodiamacrospora). A 1 to 9 visual rating indicating the resistance toDiplodia Ear Mold. A higher score indicates a higher resistance.

[0051] DIPLOID PLANT PART. Refers to a plant part or cell that has thesame diploid genotype as 35D28.

[0052] DIPROT=DIPLODIA STALK ROT SCORE. Score of stalk rot severity dueto Diplodia (Diplodia maydis). Expressed as a 1 to 9 score with 9 beinghighly resistant.

[0053] DM=PERCENT OF DRY MATTER. The percent of dry material in choppedwhole plant silage.

[0054] DRPEAR=DROPPED EARS. A measure of the number of dropped ears perplot and represents the percentage of plants that did not drop earsprior to harvest.

[0055] D/T=DROUGHT TOLERANCE. This represents a 1 to 9 rating fordrought tolerance, and is based on data obtained under stressconditions. A high score indicates good drought tolerance and a lowscore indicates poor drought tolerance.

[0056] EARHT=EAR HEIGHT. The ear height is a measure from the ground tothe highest placed developed ear node attachment and is measured incentimeters.

[0057] EARMLD=GENERAL EAR MOLD. Visual rating (1 to 9 score) where a “1”is very susceptible and a “9” is very resistant. This is based onoverall rating for ear mold of mature ears without determining thespecific mold organism, and may not be predictive for a specific earmold.

[0058] EARSZ=EAR SIZE. A 1 to 9 visual rating of ear size. The higherthe rating the larger the ear size.

[0059] EBTSTK=EARLY BRITTLE STALK. A count of the number of “snapped”plants per plot following severe winds when the corn plant isexperiencing very rapid vegetative growth in the V5-V8 stage. Expressedas percent of plants that did not snap.

[0060] ECB1LF=EUROPEAN CORN BORER FIRST GENERATION LEAF FEEDING(Ostrinia nubilalis). A 1 to 9 visual rating indicating the resistanceto preflowering leaf feeding by first generation European Corn Borer. Ahigher score indicates a higher resistance.

[0061] ECB21T=EUROPEAN CORN BORER SECOND GENERATION INCHES OF TUNNELING(Ostrinia nubilalis). Average inches of tunneling per plant in thestalk.

[0062] ECB2SC=EUROPEAN CORN BORER SECOND GENERATION (Ostrinianubilalis). A 1 to 9 visual rating indicating post flowering degree ofstalk breakage and other evidence of feeding by European Corn Borer,Second Generation. A higher score indicates a higher resistance.

[0063] ECBDPE=EUROPEAN CORN BORER DROPPED EARS (Ostrinia nubilalis).Dropped ears due to European Corn Borer. Percentage of plants that didnot drop ears under second generation corn borer infestation.

[0064] EGRWTH=EARLY GROWTH. This is a measure of the relative height andsize of a corn seedling at the 2-4 leaf stage of growth. This is avisual rating (1 to 9), with 1 being weak or slow growth, 5 beingaverage growth and 9 being strong growth. Taller plants, wider leaves,more green mass and darker color constitute a higher score.

[0065] ELITE INBRED. An inbred that contributed desirable qualities whenused to produce commercial hybrids. An elite inbred may also be used infurther breeding for the purpose of developing further improvedvarieties.

[0066] ERTLDG=EARLY ROOT LODGING. Early root lodging is the percentageof plants that do not root lodge prior to or around anthesis; plantsthat lean from the vertical axis at an approximately 30 degree angle orgreater would be counted as root lodged.

[0067] ERTLPN=EARLY ROOT LODGING. An estimate of the percentage ofplants that do not root lodge prior to or around anthesis; plants thatlean from the vertical axis at an approximately 30 degree angle orgreater would be considered as root lodged.

[0068] ERTLSC=EARLY ROOT LODGING SCORE. Score for severity of plantsthat lean from a vertical axis at an approximate 30 degree angle orgreater which typically results from strong winds prior to or aroundflowering recorded within 2 weeks of a wind event. Expressed as a 1 to 9score with 9 being no lodging.

[0069] ESTCNT=EARLY STAND COUNT. This is a measure of the standestablishment in the spring and represents the number of plants thatemerge on per plot basis for the inbred or hybrid.

[0070] EYESPT=EYE SPOT (Kabatiella zeae or Aureobasidium zeae). A 1 to 9visual rating indicating the resistance to Eye Spot. A higher scoreindicates a higher resistance.

[0071] FUSERS=FUSARIUM EAR ROT SCORE (Fusarium moniliforme or Fusariumsubglutinans). A 1, to 9 visual rating indicating the resistance toFusarium ear rot. A higher score indicates a higher resistance.

[0072] GDU=Growing Degree Units. Using the Barger Heat Unit Theory,which assumes that maize growth occurs in the temperature range 50°F.-86° F. and that temperatures outside this range slow down growth; themaximum daily heat unit accumulation is 36 and the minimum daily heatunit accumulation is 0. The seasonal accumulation of GDU is a majorfactor in determining maturity zones.

[0073] GDUSHD=GDU TO SHED. The number of growing degree units (GDUs) orheat units required for an inbred line or hybrid to have approximately50 percent of the plants shedding pollen and is measured from the timeof planting. Growing degree units are calculated by the Barger Method,where the heat units for a 24-hour period are:${GDU} = {\frac{\left( {{Max}.\quad {temp}.{+ {{Min}.\quad {temp}.}}} \right)}{2} - 50}$

[0074] The highest maximum temperature used is 86° F. and the lowestminimum temperature used is 50° F. For each inbred or hybrid it takes acertain number of GDUs to reach various stages of plant development.

[0075] GDUSLK=GDU TO SILK. The number of growing degree units requiredfor an inbred line or hybrid to have approximately 50 percent of theplants with silk emergence from time of planting. Growing degree unitsare calculated by the Barger Method as given in GDU SHD definition.

[0076] GENOTYPE. Refers to the genetic constitution of a cell ororganism.

[0077] GIBERS=GIBBERELLA EAR ROT (PINK MOLD) (Gibberella zeae). A 1 to 9visual rating indicating the resistance to Gibberella Ear Rot. A higherscore indicates a higher resistance.

[0078] GIBROT=GIBBERELLA STALK ROT SCORE. Score of stalk rot severitydue to Gibberella (Gibberella zeae). Expressed as a 1 to 9 score with 9being highly resistant.

[0079] GLFSPT=GRAY LEAF SPOT (Cercospora zeae-maydis). A 1 to 9 visualrating indicating the resistance to Gray Leaf Spot. A higher scoreindicates a higher resistance.

[0080] GOSWLT=GOSS' WILT (Corynebacterium nebraskense). A 1 to 9 visualrating indicating the resistance to Goss' Wilt. A higher score indicatesa higher resistance.

[0081] GRNAPP=GRAIN APPEARANCE. This is a 1 to 9 rating for the generalappearance of the shelled grain as it is harvested based on such factorsas the color of harvested grain, any mold on the grain, and any crackedgrain. High scores indicate good grain quality.

[0082] H/POP=YIELD AT HIGH DENSITY. Yield ability at relatively highplant densities on a 1 to 9 relative rating system with a higher numberindicating the hybrid responds well to high plant densities for yieldrelative to other hybrids. A 1, 5, and 9 would represent very poor,average, and very good yield response, respectively, to increased plantdensity.

[0083] HCBLT=HELMINTHOSPORIUM CARBONUM LEAF BLIGHT (Helminthosporiumcarbonum). A 1 to 9 visual rating indicating the resistance toHelminthosporium infection. A higher score indicates a higherresistance.

[0084] HD SMT=HEAD SMUT (Sphacelotheca reiliana). This score indicatesthe percentage of plants not infected.

[0085] HSKCVR=HUSK COVER. A 1 to 9 score based on performance relativeto key checks, with a score of 1 indicating very short husks, tip of earand kernels showing; 5 is intermediate coverage of the ear under mostconditions, sometimes with thin husk; and a 9 has husks extending andclosed beyond the tip of the ear. Scoring can best be done nearphysiological maturity stage or any time during dry down untilharvested.

[0086] INC D/A=GROSS INCOME (DOLLARS PER ACRE). Relative income per acreassuming drying costs of two cents per point above 15.5 percent harvestmoisture and current market price per bushel.

[0087] INCOME/ACRE. Income advantage of hybrid to be patented over otherhybrid on per acre basis.

[0088] INC ADV=GROSS INCOME ADVANTAGE. GROSS INCOME advantage of variety#1 over variety #2.

[0089] KSZDCD=KERNEL SIZE DISCARD. The percent of discard seed;calculated as the sum of discarded tip kernels and extra large kernels.

[0090] LINKAGE. Refers to a phenomenon wherein alleles on the samechromosome tend to segregate together more often than expected by chanceif their transmission was independent.

[0091] LINKAGE DISEQUILIBRIUM. Refers to a phenomenon wherein allelestend to remain together in linkage groups when segregating from parentsto offspring, with a greater frequency than expected from theirindividual frequencies.

[0092] L/POP=YIELD AT LOW DENSITY. Yield ability at relatively low plantdensities on a 1 to 9 relative system with a higher number indicatingthe hybrid responds well to low plant densities for yield relative toother hybrids. A 1, 5, and 9 would represent very poor, average, andvery good yield response, respectively, to low plant density.

[0093] LRTLDG=LATE ROOT LODGING. Late root lodging is the percentage ofplants that do not root lodge after anthesis through harvest; plantsthat lean from the vertical axis at an approximately 30 degree angle orgreater would be counted as root lodged.

[0094] LRTLPN=LATE ROOT LODGING. Late root lodging is an estimate of thepercentage of plants that do not root lodge after anthesis throughharvest; plants that lean from the vertical axis at an approximately 30degree angle or greater would be considered as root lodged.

[0095] LRTLSC=LATE ROOT LODGING SCORE. Score for severity of plants thatlean from a vertical axis at an approximate 30 degree angle or greaterwhich typically results from strong winds after flowering. Recordedprior to harvest when a root-lodging event has occurred. This lodgingresults in plants that are leaned or “lodged” over at the base of theplant and do not straighten or “goose-neck” back to a vertical position.Expressed as a 1 to 9 score with 9 being no lodging.

[0096] MDMCPX=MAIZE DWARF MOSAIC COMPLEX (MDMV=Maize Dwarf Mosaic Virusand MCDV=Maize Chlorotic Dwarf Virus). A 1 to 9 visual rating indicatingthe resistance to Maize Dwarf Mosaic Complex. A higher score indicates ahigher resistance.

[0097] MST=HARVEST MOISTURE. The moisture is the actual percentagemoisture of the grain at harvest.

[0098] MSTADV=MOISTURE ADVANTAGE. The moisture advantage of variety #1over variety #2 as calculated by: MOISTURE of variety #2—MOISTURE ofvariety #1=MOISTURE ADVANTAGE of variety #1.

[0099] NLFBLT=NORTHERN LEAF BLIGHT (Helminthosporium turcicum orExserohilum turcicum). A 1 to 9 visual rating indicating the resistanceto Northern Leaf Blight. A higher score indicates a higher resistance.

[0100] OILT=GRAIN OIL. Absolute value of oil content of the kernel aspredicted by Near-Infrared Transmittance and expressed as a percent ofdry matter.

[0101] PEDIGREE DISTANCE=Relationship among generations based on theirancestral links as evidenced in pedigrees. May be measured by thedistance of the pedigree from a given starting point in the ancestry.

[0102] PERCENT IDENTITY. Percent identity as used herein refers to thecomparison of the alleles of two plants or lines as scored by matchingloci. Percent identity is determined by comparing a statisticallysignificant number of the loci of two plants or lines and scoring amatch when the same two alleles are present at the same loci for eachplant. For example, a percent identity of 90% between hybrid 35D28 andanother plant means that the two plants have the same two alleles at 90%of their loci.

[0103] PERCENT SIMILARITY. Percent similarity as used herein refers tothe comparison of the alleles of two plants or lines as scored bymatching alleles. Percent similarity is determined by comparing astatistically significant number of the loci of two plants or lines andscoring one allele match when the same allele is present at the sameloci for each plant and two allele matches when the same two alleles arepresent at the same loci for each plant. A percent similarity of 90%between hybrid 35D28 and another plant means that the two plants have90% matching alleles.

[0104] PLANT. As used herein, the term “plant” includes reference to animmature or mature whole plant, including a plant that has beendetasseled or from which seed or grain has been removed. Seed or embryothat will produce the plant is also considered to be the plant.

[0105] PLANT PARTS. As used herein, the term “plant parts” includesleaves, stems, roots, seed, grain, embryo, pollen, ovules, flowers,ears, cobs, husks, stalks, root tips, anthers, pericarp, silk, tissue,cells and the like.

[0106] PLTHT=PLANT HEIGHT. This is a measure of the height of the plantfrom the ground to the tip of the tassel in centimeters.

[0107] POLSC=POLLEN SCORE. A 1 to 9 visual rating indicating the amountof pollen shed. The higher the score the more pollen shed.

[0108] POLWT=POLLEN WEIGHT. This is calculated by dry weight of tasselscollected as shedding commences minus dry weight from similar tasselsharvested after shedding is complete.

[0109] POP K/A=PLANT POPULATIONS. Measured as 1000s per acre.

[0110] POP ADV=PLANT POPULATION ADVANTAGE. The plant populationadvantage of variety #1 over variety #2 as calculated by PLANTPOPULATION of variety #2—PLANT POPULATION of variety #1=PLANT POPULATIONADVANTAGE of variety #1.

[0111] PRM=PREDICTED RELATIVE MATURITY. This trait, predicted relativematurity, is based on the harvest moisture of the grain. The relativematurity rating is based on a known set of checks and utilizes standardlinear regression analyses and is also referred to as the ComparativeRelative Maturity Rating System that is similar to the MinnesotaRelative Maturity Rating System.

[0112] PRMSHD=A relative measure of the growing degree units (GDU)required to reach 50% pollen shed. Relative values are predicted valuesfrom the linear regression of observed GDU's on relative maturity ofcommercial checks.

[0113] PROT=GRAIN PROTEIN. Absolute value of protein content of thekernel as predicted by Near-Infrared Transmittance and expressed as apercent of dry matter.

[0114] RTLDG=ROOT LODGING. Root lodging is the percentage of plants thatdo not root lodge; plants that lean from the vertical axis at anapproximately 30 degree angle or greater would be counted as rootlodged.

[0115] RTLADV=ROOT LODGING ADVANTAGE. The root lodging advantage ofvariety #1 over variety #2.

[0116] SCTGRN=SCATTER GRAIN. A 1 to 9 visual rating indicating theamount of scatter grain (lack of pollination or kernel abortion) on theear. The higher the score the less scatter grain.

[0117] SDGVGR=SEEDLING VIGOR. This is the visual rating (1 to 9) of theamount of vegetative growth after emergence at the seedling stage(approximately five leaves). A higher score indicates better vigor.

[0118] SEL IND=SELECTION INDEX. The selection index gives a singlemeasure of the hybrid's worth based on information for up to fivetraits. A maize breeder may utilize his or her own set of traits for theselection index. One of the traits that is almost always included isyield. The selection index data presented in the tables represent themean value averaged across testing stations.

[0119] SIL DMP=SILAGE DRY MATTER. The percent of dry material in choppedwhole plant silage.

[0120] SELF POLLINATION. A plant is self-pollinated if pollen from oneflower is transferred to the same or another flower of the same plant.

[0121] SIB POLLINATION. A plant is sib-pollinated when individualswithin the same family or line are used for pollination.

[0122] SLFBLT=SOUTHERN LEAF BLIGHT (Helminthosporium maydis or Bipolarismaydis). A 1 to 9 visual rating indicating the resistance to SouthernLeaf Blight. A higher score indicates a higher resistance.

[0123] SOURST=SOUTHERN RUST (Puccinia polysora). A 1 to 9 visual ratingindicating the resistance to Southern Rust. A higher score indicates ahigher resistance.

[0124] STAGRN=STAY GREEN. Stay green is the measure of plant health nearthe time of black layer formation (physiological maturity). A high scoreindicates better late-season plant health.

[0125] STARCH=PERCENT OF STARCH. The percent of dry matter that isstarch in chopped whole plant forage.

[0126] STDADV=STALK STANDING ADVANTAGE. The advantage of variety #1 overvariety #2 for the trait STK CNT.

[0127] STKCNT=NUMBER OF PLANTS. This is the final stand or number ofplants per plot.

[0128] STKLDG=STALK LODGING REGULAR. This is the percentage of plantsthat did not stalk lodge (stalk breakage) at regular harvest (when grainmoisture is between about 20 and 30%) as measured by either naturallodging or pushing the stalks and determining the percentage of plantsthat break below the ear.

[0129] STKLDL=LATE STALK LODGING. This is the percentage of plants thatdid not stalk lodge (stalk breakage) at or around late season harvest(when grain moisture is between about 15 and 18%) as measured by eithernatural lodging or pushing the stalks and determining the percentage ofplants that break below the ear.

[0130] STKLDS=STALK LODGING SCORE. A plant is considered as stalk lodgedif the stalk is broken or crimped between the ear and the ground. Thiscan be caused by any or a combination of the following: strong windslate in the season, disease pressure within the stalks, ECB damage orgenetically weak stalks. This trait should be taken just prior to or atharvest. Expressed on a 1 to 9 scale with 9 being no lodging.

[0131] STLLPN=LATE STALK LODGING. This is the percent of plants that didnot stalk lodge (stalk breakage or crimping) at or around late seasonharvest (when grain moisture is below 20%) as measured by either naturallodging or pushing the stalks and determining the percentage of plantsthat break or crimp below the ear.

[0132] STLPCN=STALK LODGING REGULAR. This is an estimate of thepercentage of plants that did not stalk lodge (stalk breakage at regularharvest (when grain moisture is between about 20 and 30%) as measured byeither natural lodging or pushing the stalks and determining thepercentage of plants that break below the ear.

[0133] STRT=GRAIN STARCH. Absolute value of starch content of the kernelas predicted by Near-Infrared Transmittance and expressed as a percentof dry matter.

[0134] STWWLT=Stewart's Wilt (Erwinia stewartil). A 1 to 9 visual ratingindicating the resistance to Stewart's Wilt. A higher score indicates ahigher resistance.

[0135] TASBLS=TASSEL BLAST. A 1 to 9 visual rating was used to measurethe degree of blasting (necrosis due to heat stress) of the tassel atthe time of flowering. A 1 would indicate a very high level of blastingat time of flowering, while a 9 would have no tassel blasting.

[0136] TASSZ=TASSEL SIZE. A 1 to 9 visual rating was used to indicatethe relative size of the tassel. The higher the rating the larger thetassel.

[0137] TAS WT=TASSEL WEIGHT. This is the average weight of a tassel(grams) just prior to pollen shed.

[0138] TDM/HA=TOTAL DRY MATTER PER HECTARE. Yield of total dry plantmaterial in metric tons per hectare.

[0139] TEXEAR=EAR TEXTURE. A 1 to 9 visual rating was used to indicatethe relative hardness (smoothness of crown) of mature grain. A 1 wouldbe very soft (extreme dent) while a 9 would be very hard (flinty or verysmooth crown).

[0140] TILLER=TILLERS. A count of the number of tillers per plot thatcould possibly shed pollen was taken. Data are given as a percentage oftillers: number of tillers per plot divided by number of plants perplot.

[0141] TST WT=TEST WEIGHT (UNADJUSTED). The measure of the weight of thegrain in pounds for a given volume (bushel).

[0142] TSWADV=TEST WEIGHT ADVANTAGE. The test weight advantage ofvariety #1 over variety #2.

[0143] WIN M %=PERCENT MOISTURE WINS.

[0144] WIN Y %=PERCENT YIELD WINS.

[0145] YIELD=YIELD OF SILAGE. Yield in tons per acre at 30% dry matter.

[0146] YIELD BU/A=YIELD (BUSHELS/ACRE). Yield of the grain at harvest inbushels per acre adjusted to 15% moisture.

[0147] YLDADV=YIELD ADVANTAGE. The yield advantage of variety #1 overvariety #2 as calculated by: YIELD of variety #1—YIELD variety #2=yieldadvantage of variety #1.

[0148] YLD SC=YIELD SCORE. A 1 to 9 visual rating was used to give arelative rating for yield based on plot ear piles. The higher the ratingthe greater visual yield appearance.

[0149] Definitions for Area of Adaptability

[0150] When referring to area of adaptability, such term is used todescribe the location with the environmental conditions that would bewell suited for this maize line. Area of adaptability is based on anumber of factors, for example: days to maturity, insect resistance,disease resistance, and drought resistance. Area of adaptability doesnot indicate that the maize line will grow in every location within thearea of adaptability or that it will not grow outside the area.

[0151] Central Corn Belt: Iowa, Illinois, Indiana

[0152] Drylands: non-irrigated areas of North Dakota, South Dakota,Nebraska, Kansas, Colorado and Oklahoma

[0153] Eastern U.S.: Ohio, Pennsylvania, Delaware, Maryland, Virginia,and West Virginia

[0154] North central U.S.: Minnesota and Wisconsin

[0155] Northeast: Michigan, New York, Vermont, and Ontario and QuebecCanada

[0156] Northwest U.S.: North Dakota, South Dakota, Wyoming, Washington,Oregon, Montana, Utah, and Idaho

[0157] South central U.S.: Missouri, Tennessee, Kentucky, Arkansas

[0158] Southeast U.S.: North Carolina, South Carolina, Georgia, Florida,Alabama, Mississippi, and Louisiana

[0159] Southwest U.S.: Texas, Oklahoma, New Mexico, Arizona

[0160] Western U.S.: Nebraska, Kansas, Colorado, and California

[0161] Maritime Europe: Northern France, Germany, Belgium, Netherlandsand Austria

DETAILED DESCRIPTION OF THE INVENTION

[0162] Inbred maize lines are typically developed for use in theproduction of hybrid maize lines. Maize hybrids need to be highlyhomogeneous, heterozygous and reproducible to be useful as commercialhybrids. There are many analytical methods available to determine theheterozygous nature and the identity of these lines.

[0163] The oldest and most traditional method of analysis is theobservation of phenotypic traits. The data is usually collected in fieldexperiments over the life of the maize plants to be examined. Phenotypiccharacteristics most often observed are for traits associated with plantmorphology, ear and kernel morphology, insect and disease resistance,maturity, and yield.

[0164] In addition to phenotypic observations, the genotype of a plantcan also be examined. A plant's genotype can be used to identify plantsof the same variety or a related variety. For example, the genotype canbe used to determine the pedigree of a plant. There are manylaboratory-based techniques available for the analysis, comparison andcharacterization of plant genotype; among these are IsozymeElectrophoresis, Restriction Fragment Length Polymorphisms (RFLPs),Randomly Amplified Polymorphic DNAs (RAPDs), Arbitrarily PrimedPolymerase Chain Reaction (AP-PCR), DNA Amplification Fingerprinting(DAF), Sequence Characterized Amplified Regions (SCARs), AmplifiedFragment Length Polymorphisms (AFLPs), Simple Sequence Repeats (SSRs)which are also referred to as Microsatellites, and Single NucleotidePolymorphisms (SNPs).

[0165] Isozyme Electrophoresis and RFLPs as discussed in Lee, M.,“Inbred Lines of Maize and Their Molecular Markers,” The Maize Handbook,(Springer-Verlag, New York, Inc. 1994, at 423-432) incorporated hereinby reference, have been widely used to determine genetic composition.Isozyme Electrophoresis has a relatively low number of available markersand a low number of allelic variants. RFLPs allow more discriminationbecause they have a higher degree of allelic variation in maize and alarger number of markers can be found. Both of these methods have beeneclipsed by SSRs as discussed in Smith et al., “An evaluation of theutility of SSR loci as molecular markers in maize (Zea mays L.):comparisons with data from RFLPs and pedigree”, Theoretical and AppliedGenetics (1997) vol. 95 at 163-173 and by Pejic et al., “Comparativeanalysis of genetic similarity among maize inbreds detected by RFLPs,RAPDs, SSRs, and AFLPs,” Theoretical and Applied Genetics (1998) at1248-1255 incorporated herein by reference. SSR technology is moreefficient and practical to use than RFLPs; more marker loci can beroutinely used and more alleles per marker locus can be found using SSRsin comparison to RFLPs. Single Nucleotide Polymorphisms may also be usedto identify the unique genetic composition of the invention and progenylines retaining that unique genetic composition. Various molecularmarker techniques may be used in combination to enhance overallresolution.

[0166] Maize DNA molecular marker linkage maps have been rapidlyconstructed and widely implemented in genetic studies. One such study isdescribed in Boppenmaier, et al., “Comparisons among strains of inbredsfor RFLPs”, Maize Genetics Cooperative Newsletter, 65:1991, pg. 90, isincorporated herein by reference.

[0167] Pioneer Brand Hybrid 35D28 is characterized by excellent yieldand above average root lodging resistance. Hybrid 35D28 furtherdemonstrates rapid drydown, vigorous early plant growth, highextractable grain starch and tolerance to Goss' Wilt, to Gray Leaf Spot,to Northern Leaf Blight, to Head Smut, to Anthracnose Stalk Rot, and toFusarium Ear and Kernel Rot as well as tolerance to Gibberella Ear Rot.The hybrid is particularly suited to Canada and to the Central CornBelt, Northeast, and Eastern areas of the United States.

[0168] Pioneer Brand Hybrid 35D28 is a single cross, yellow endosperm,dent-flint maize hybrid. Hybrid 35D28 has a relative maturity ofapproximately 106 based on the Comparative Relative Maturity RatingSystem for harvest moisture of grain.

[0169] This hybrid has the following characteristics based on the datacollected primarily at Johnston, Iowa. TABLE 1 VARIETY DESCRIPTIONINFORMATION 35D28 AVG STDEV N 1. TYPE: (Describe intermediate types incomments section) 1 = Sweet, 2 = Dent, 3 = Flint, 4 = Flour, 5 = Pop and2 6 = Ornamental. Comments: Dent-Flint 2. MATURITY: DAYS HEAT UNITS DaysH.Units Emergence to 50% of plants in silk 60 1,266 Emergence to 50% ofplants in pollen shed 61 1,274 10% to 90% pollen shed 2 42 50% Silk toharvest at 25% moisture 3. PLANT: Plant Height (to tassel tip) (cm)315.6 8.46 15 Ear Height (to base of top ear node) (cm) 121.2 15.29 15Length of Top Ear Internode (cm) 17.9 2.58 15 Average Number of Tillersper Plant 0.0 0.01 3 Average Number of Ears per Stalk 1.0 0.03 3Anthocyanin of Brace Roots: 1 = Absent, 2 = Faint, 2 3 = Moderate, 4 =Dark 4. LEAF: Width of Ear Node Leaf (cm) 9.9 0.96 15 Length of Ear NodeLeaf (cm) 92.2 3.03 15 Number of Leaves above Top Ear 7.7 0.72 15 LeafAngle: (at anthesis, 2nd leaf above ear to 30.2 5.39 15 stalk aboveleaf) (Degrees) *Leaf Color: V. Dark Green Munsell: 7.5GY34 Leaf SheathPubescence: 1 = none to 9 = like peach fuzz 5 5. TASSEL: Number ofPrimary Lateral Branches 4.3 2.32 15 Branch Angle from Central Spike31.7 12.19 15 Tassel Length: (from peduncle node totassel tip),(cm).63.6 3.76 15 Pollen Shed: 0 = male sterile, 9 = heavy shed 7 *AntherColor: Pink Munsell: 10R56 *Glume Color: Med. Green Munsell: 7.5GY56*Bar Glumes (glume bands): 1 = absent, 2 = present 1 Peduncle Length:(from top leaf node to lower florets or 25.5 4.79 15 branches),(cm). 6a.EAR (Unhusked ear) AVG STDEV N *Silk color: Red Munsell: 7.5RP38 (3 daysafter silk emergence) *Fresh husk color: Med. Green Munsell: 5GY78 *Dryhusk color: Buff Munsell: 2.5Y8.54 (65 days after 50% silking) Earposition at dry husk stage: 1 = upright, 2 = horizontal, 3 3 = pendantHusk Tightness: (1 = very loose, 9 = very tight) 4 Husk Extension (atharvest):1 = short(ears exposed), 2 2 = medium (<8 cm), 3 = long (8-10cm), 4 = v. long (>10 cm) 6b. EAR (Husked ear data) Ear Length (cm):19.9 1.41 15 Ear Diameter at mid-point (mm) 45.1 1.92 15 Ear Weight(gm): 194.5 37.01 15 Number of Kernel Rows: 17.5 0.92 15 Kernel Rows: 1= indistinct, 2 = distinct 2 Row Alignment: 1 = straight, 2 = slightlycurved, 3 = spiral 1 Shank Length (cm): 14.3 2.69 15 Ear Taper: 1 =slight cylind., 2 = average, 3 = extreme 2 7. KERNEL (Dried): KernelLength (mm): 12.1 0.80 15 Kernel Width (mm): 7.9 0.59 15 KernelThickness (mm): 5.1 0.52 15 Round Kernels (shape grade) (%) 35.4 14.79 3Aleurone Color Pattern: 1 = homozygous, 2 = segregating 1 *AleuroneColor: Yellow Munsell: 10YR714 *Hard Endo. Color: Yellow Munsell:10YR712 Endosperm Type: 3 1 = sweet (su1), 2 = extra sweet (sh2), 3 =normal starch, 4 = high amylose starch, 5 = waxy starch, 6 = highprotein, 7 = high lysine, 8 = super sweet (se), 9 = high oil, 10 = otherWeight per 100 Kernels (unsized sample) (gm): 29.0 2.65 3 8. COB: *CobDiameter at mid-point (mm): 24.8 0.86 15 *Cob Color: Pink OrangeMunsell: 2.5YR48 10. DISEASE RESISTANCE: (Rate from 1 = most-susceptibleto 9 = most-resistant. Leave blank if not tested, leave race or strainoptions blank if polygenic.) A. LEAF BLIGHTS, WILTS, AND LOCAL INFECTIONDISEASES Anthracnose Leaf Blight (Colletotrichum graminicola) CommonRust (Puccinia sorghi) Common Smut (Ustilago maydis) Eyespot (Kabatiellazeae) 8 Goss' Wilt (Clavibacter michiganense spp. nebraskense) 5 GrayLeaf Spot (Cercospora zeae-maydis) Helminthosporium Leaf Spot (Bipolariszeicola) Race: 6 Northern Leaf Blight (Exserohilum turcicum) Race:Southern Leaf Blight (Bipolaris maydis) Race: Southern Rust (Pucciniapolysora) Stewart's Wilt (Erwinia stewartii) Other (Specify):                                         B. SYSTEMIC DISEASES 4 CornLethal Necrosis (MCMV and MDMV) 9 Head Smut (Sphacelotheca reiliana)Maize Chlorotic Dwarf Virus (MDV) Maize Chlorotic Mottle Virus (MCMV)Maize Dwarf Mosaic Virus (MDMV) Sorghum Downy Mildew of Corn(Peronosclerospora sorghi) Other (Specify):                                         C. STALK ROTS 5 AnthracnoseStalk Rot (Colletotrichum graminicola) Diplodia Stalk Rot (Stenocarpellamaydis) Fusarium Stalk Rot (Fusarium moniliforme) Gibberella Stalk Rot(Gibberella zeae) Other (Specify):                                         D. EAR AND KERNEL ROTSAspergillus Ear and Kernel Rot (Aspergillus flavus) 4 Diplodia Ear Rot(Stenocarpella maydis) 5 Fusarium Ear and Kernel Rot (Fusariummoniliforme) 6 Gibberella Ear Rot (Gibberella zeae) Other (Specify):                                         11. INSECT RESISTANCE: (Ratefrom 1 = most-suscept. to 9 = most-resist., leave blank if not tested.)Corn Worm (Helicoverpa zea)     Leaf Feeding     Silk Feeding     EarDamage Corn Leaf Aphid (Rophalosiphum maydis) Corn Sap Beetle(Capophilus dimidiatus) European Corn Borer (Ostrinia nubilalis) 1st.Generation (Typically whorl leaf feeding) 2nd. Generation (Typicallyleaf sheath-collar feeding)     Stalk Tunneling     cm tunneled/plantFall armyworm (Spodoptera fruqiperda)     Leaf Feeding     Silk Feeding    mg larval wt. Maize Weevil (Sitophilus zeamaize) Northern Rootworm(Diabrotica barberi) Southern Rootworm (Diabrotica undecimpunctata)Southwestern Corn Borer (Diatreaea grandiosella)     Leaf Feeding    Stalk Tunneling     cm tunneled/plant Two-spotted Spider Mite(Tetranychus utricae) Western Rootworm (Diabrotica virgifrea virgifrea)Other (Specify):                                          12. AGRONOMICTRAITS: 5 Staygreen (at 65 days after anthesis; rate from 1-worst to9-excellent) % Dropped Ears (at 65 days after anthesis) % Pre-anthesisBrittle Snapping % Pre-anthesis Root Lodging % Post-anthesis RootLodging (at 65 days after anthesis) % Post-anthesis Stalk Lodging11,620.0 Kg/ha (Yield at 12-13% grain moisture)

Research Comparisons for Pioneer Hybrid 35D28

[0170] Comparisons of characteristics for Pioneer Brand Hybrid 35D28were made against Hybrid 35Y65, 35Y54, 34G81, 34D71, 34H31, 34M94 and36N70.

[0171] Table 2A compares Pioneer Brand Hybrid 35D28 and Hybrid 35Y65, ahybrid with similar maturity. The table demonstrates significantdifferences between Hybrid 35D28 and Hybrid 35Y65 which include numberof growing degree units to pollen shed and to silk emergence, stalkcount, stay green and resistance to Northern Leaf Blight.

[0172] Table 2B compares Pioneer Brand Hybrid 35D28 and Hybrid 35Y54, aclosely related hybrid with similar maturity. Significant differencesbetween Hybrid 35D28 and Hybrid 35Y54 include yield, early growth score,number of growing degree units to pollen shed and to silk emergence,stalk count, test weight and late season root lodging resistance.

[0173] Table 2C compares Pioneer Brand Hybrid 35D28 and Hybrid 34G81, aclosely related hybrid. The table demonstrates significant differencesbetween Hybrid 35D28 and Hybrid 34G81 which include yield and number ofgrowing degree units to pollen shed.

[0174] Table 2D compares Pioneer Brand Hybrid 35D28 and Hybrid 34D71, aclosely related hybrid. Only a few traits are reported in the table, andsignificant differences between Hybrid 35D28 and Hybrid 34D71 are shown,it is expected that other significant differences would be observed iffurther traits were examined.

[0175] Table 2E compares Pioneer Brand Hybrid 35D28 and Hybrid 34H31, ahybrid with a similar area of adaptation. The table demonstratessignificant differences between Hybrid 35D28 and Hybrid 34H31 whichinclude harvest moisture and number of growing degree units to pollenshed and to silk emergence.

[0176] Table 2F compares Pioneer Brand Hybrid 35D28 and Hybrid 34M94, ahybrid with a similar area of adaptation. Significant differencesbetween Hybrid 35D28 and Hybrid 39M94 include yield, harvest moisture,number of growing degree units to silk emergence, resistance to NorthernLeaf Blight, resistance to Anthracnose Stalk Rot, resistance to HeadSmut and late season root lodging resistance.

[0177] Table 2G compares Pioneer Brand Hybrid 35D28 and Hybrid 36N70, ahybrid with a similar area of adaptation. The table demonstratessignificant differences between Hybrid 35D28 and Hybrid 36N70 whichincludes yield. TABLE 2A HYBRID COMPARISON Variety #1: 35D28 Variety #2:35Y65 YIELD YIELD MST EGRWTH ESTCNT GDUSHD BU/A 56# BU/A 56# PCT SCORECOUNT GDU Stat ABS % MN % MN % MN % MN % MN Mean1 182.5 103.0 99.1 96.6103.9 102.6 Mean2 179.6 101.3 97.9 95.0 104.2 98.6 Locs 106 106 106 19 829 Reps 118 118 118 21 12 38 Diff 2.9 1.7 −1.3 1.6 −0.3 4.1 Prob 0.1590.191 0.108 0.811 0.919 0.000 GDUSLK STKCNT PLTHT EARHT STAGRN ABTSTKGDU COUNT CM CM SCORE % NOT Stat % MN % MN % MN % MN % MN % MN Mean1102.9 100.5 105.5 108.3 113.7 124.1 Mean2 97.5 99.1 96.9 98.5 78.2 92.8Locs 25 188 23 21 39 3 Reps 33 276 29 24 44 18 Diff 5.4 1.4 8.6 9.8 35.431.2 Prob 0.000 0.000 0.000 0.000 0.000 0.400 TSTWT GLFSPT NLFBLT GOSWLTANTROT CLN LB/BU SCORE SCORE SCORE SCORE SCORE Stat ABS ABS ABS ABS ABSABS Mean1 55.2 4.4 5.5 7.8 4.3 3.7 Mean2 56.1 4.3 3.7 5.8 3.5 5.3 Locs56 4 11 2 3 1 Reps 60 6 18 4 6 3 Diff −0.9 0.1 1.7 2.0 0.8 −1.7 Prob0.000 0.846 0.003 0.156 0.130 FUSERS GIBERS DIPERS ECBDPE ECB1LF ECB2SCSCORE SCORE SCORE % NOT SCORE SCORE Stat ABS ABS ABS ABS ABS ABS Mean15.2 7.8 3.5 97.3 3.7 5.0 Mean2 5.5 8.5 3.0 99.0 4.3 5.5 Locs 7 2 1 7 1 9Reps 11 3 2 8 3 13 Diff −0.3 −0.8 0.5 −1.7 −0.7 −0.5 Prob 0.508 0.5000.017 0.420 HSKCVR GIBROT DIPROT BRTSTK HDSMT ERTLPN LRTLPN SCORE SCORESCORE % NOT % NOT % NOT % NOT Stat ABS ABS ABS ABS ABS ABS ABS Mean1 5.94.1 3.8 100.0 99.8 82.1 90.7 Mean2 6.4 3.9 4.3 99.6 98.2 74.1 98.2 Locs7 8 2 4 6 9 11 Reps 8 15 4 4 8 11 13 Diff −0.5 0.3 −0.5 0.4 1.6 8.0 −7.5Prob 0.356 0.788 0.705 0.391 0.203 0.601 0.122

[0178] TABLE 2B HYBRID COMPARISON Variety #1: 35D28 Variety #2: 35Y54YIELD YIELD MST EGRWTH ESTCNT GDUSHD BU/A 56# BU/A 56# PCT SCORE COUNTGDU Stat ABS % MN % MN % MN % MN % MN Mean1 186.5 103.8 98.9 98.4 104.7102.6 Mean2 179.3 100.0 98.7 73.4 102.6 98.3 Locs 123 123 123 17 6 35Reps 134 134 134 17 8 45 Diff 7.2 3.8 −0.2 25.0 2.2 4.2 Prob 0.000 0.0010.747 0.000 0.464 0.000 GDUSLK STKCNT PLTHT EARHT STAGRN STKLDS GDUCOUNT CM CM SCORE SCORE Stat % MN % MN % MN % MN % MN ABS Mean1 102.7100.4 105.2 107.4 109.5 6.0 Mean2 98.6 99.4 96.3 93.0 103.5 8.0 Locs 28205 30 28 45 1 Reps 37 284 37 31 49 1 Diff 4.1 1.0 8.9 14.4 6.0 −2.0Prob 0.000 0.002 0.000 0.000 0.425 ABTSTK DRPEAR TSTWT GLFSPT NLFBLTGOSWLT % NOT % NOT LB/BU SCORE SCORE SCORE Stat % MN % MN ABS ABS ABSABS Mean1 124.1 100.7 55.2 4.9 5.5 7.8 Mean2 115.7 99.2 54.1 4.7 7.0 7.8Locs 3 2 67 6 11 2 Reps 18 2 70 8 18 4 Diff 8.4 1.5 1.2 0.3 −1.6 0.0Prob 0.432 0.003 0.000 0.518 0.001 1.000 ANTROT CLN FUSERS GIBERS DIPERSECBDPE SCORE SCORE SCORE SCORE SCORE % NOT Stat ABS ABS ABS ABS ABS ABSMean1 4.3 3.7 5.2 6.2 3.5 97.3 Mean2 3.5 5.3 5.6 5.0 4.5 98.8 Locs 3 1 73 1 7 Reps 6 3 11 4 2 8 Diff 0.8 −1.7 −0.4 1.2 −1.0 −1.4 Prob 0.3000.543 0.499 0.076 ECB1LF ECB2SC HSKCVR GIBROT DIPROT BRTSTK SCORE SCORESCORE SCORE SCORE % NOT Stat ABS ABS ABS ABS ABS ABS Mean1 3.7 4.9 6.03.9 3.8 99.3 Mean2 3.3 4.7 5.7 3.1 6.3 99.5 Locs 1 12 6 7 2 7 Reps 3 166 14 4 7 Diff 0.3 0.2 0.3 0.7 −2.5 −0.2 Prob 0.741 0.363 0.539 0.2420.787 HDSMT ERTLPN LRTLPN % NOT % NOT % NOT Stat ABS ABS ABS Mean1 99.880.9 90.6 Mean2 98.2 66.3 81.6 Locs 6 10 12 Reps 8 12 14 Diff 1.6 14.69.0 Prob 0.077 0.223 0.040

[0179] TABLE 2C HYBRID COMPARISON Variety #1: 35D28 Variety #2: 34G81YIELD YIELD MST EGRWTH ESTCNT BU/A 56# BU/A 56# PCT SCORE COUNT Stat ABS% MN % MN % MN % MN Mean1 180.8 108.1 102.1 109.4 101.3 Mean2 170.5101.9 99.4 109.7 100.6 Locs 17 17 17 2 2 Reps 17 17 17 2 4 Diff 10.3 6.3−2.7 −0.4 0.7 Prob 0.021 0.026 0.125 0.987 0.817 GDUSHD GDUSLK STKCNTPLTHT EARHT GDU GDU COUNT CM CM Stat % MN % MN % MN % MN % MN Mean1103.0 103.4 101.2 102.3 101.9 Mean2 100.9 103.0 100.7 98.3 98.9 Locs 7 250 11 11 Reps 7 2 63 11 11 Diff 2.0 0.4 0.5 4.0 3.1 Prob 0.039 0.8600.517 0.016 0.321 STAGRN LRTLSC STKLDS STKLDG TSTWT SCORE SCORE SCORE %NOT LB/BU Stat % MN ABS ABS % MN ABS Mean1 106.2 9.0 7.6 99.2 55.0 Mean287.5 9.0 6.8 96.1 55.7 Locs 7 1 10 2 13 Reps 9 1 10 2 13 Diff 18.7 0.00.8 3.1 −0.6 Prob 0.059 0.104 0.846 0.139 NLFBLT ANTROT HSKCVR BRTSTKSCORE SCORE SCORE % NOT Stat ABS ABS ABS ABS Mean1 7.0 6.0 6.0 98.2Mean2 8.0 4.0 6.0 98.3 Locs 1 1 1 1 Reps 1 1 1 1 Diff −1.0 2.0 0.0 0.0Prob

[0180] TABLE 2D HYBRID COMPARISON Variety #1: 35D28 Variety #2: 34D71YIELD YIELD MST EGRWTH ESTCNT STKCNT BU/A 56# BU/A 56# PCT SCORE COUNTCOUNT Stat ABS % MN % MN % MN % MN % MN Mean1 174.9 103.5 104.3 80.9101.3 99.9 Mean2 172.1 101.4 112.9 119.0 106.4 101.5 Locs 2 2 2 2 2 24Reps 4 4 4 4 4 46 Diff 2.8 2.1 8.6 −38.0 −5.1 −1.6 Prob 0.793 0.7530.386 0.040 0.130 0.039 PLTHT EARHT STAGRN TSTWT HSKCVR HDSMT CM CMSCORE LB/BU SCORE % NOT Stat % MN % MN % MN ABS ABS ABS Mean1 99.0 109.7106.8 51.5 5.5 98.8 Mean2 96.5 98.7 137.2 52.2 5.5 91.4 Locs 1 1 3 1 1 2Reps 1 1 6 2 2 4 Diff 2.5 11.0 −30.4 −0.8 0.0 7.4 Prob 0.495 0.316

[0181] TABLE 2E HYBRID COMPARISON Variety #1: 35D28 Variety #2: 34H31YIELD YIELD MST EGRWTH ESTCNT GDUSHD BU/A 56# BU/A 56# PCT SCORE COUNTGDU Stat ABS % MN % MN % MN % MN % MN Mean1 176.7 102.3 98.3 96.6 103.9102.6 Mean2 176.3 102.2 107.5 91.4 103.1 99.6 Locs 138 138 139 19 8 29Reps 151 151 152 21 12 39 Diff 0.5 0.1 9.3 5.2 0.8 3.0 Prob 0.766 0.9560.000 0.216 0.504 0.000 GDUSLK STKCNT PLTHT EARHT STAGRN ABTSTK GDUCOUNT CM CM SCORE % NOT Stat % MN % MN % MN % MN % MN % MN Mean1 102.9100.4 105.5 108.3 113.7 124.1 Mean2 99.2 100.6 98.6 99.3 117.3 94.0 Locs25 192 23 21 39 3 Reps 34 286 30 24 44 18 Diff 3.7 −0.2 6.9 9.0 −3.630.1 Prob 0.000 0.713 0.000 0.000 0.599 0.378 DRPEAR TSTWT GLFSPT NLFBLTGOSWLT ANTROT % NOT LB/BU SCORE SCORE SCORE SCORE Stat % MN ABS ABS ABSABS ABS Mean1 101.0 55.7 4.4 5.5 7.8 4.3 Mean2 101.0 57.9 5.4 6.5 8.04.3 Locs 1 86 4 11 2 3 Reps 1 90 6 18 4 6 Diff 0.0 −2.2 −1.0 −1.0 −0.30.0 Prob 0.000 0.092 0.005 0.500 1.000 CLN FUSERS GIBERS DIPERS ECBDPEECB1LF SCORE SCORE SCORE SCORE % NOT SCORE Stat ABS ABS ABS ABS ABS ABSMean1 3.7 5.2 7.8 3.5 97.3 3.7 Mean2 4.3 6.2 8.1 5.0 96.0 2.7 Locs 1 7 21 7 1 Reps 3 11 3 2 8 3 Diff −0.7 −1.0 −0.3 −1.5 1.3 1.0 Prob 0.0860.889 0.347 ECB2SC HSKCVR GIBROT DIPROT BRTSTK HDSMT SCORE SCORE SCORESCORE % NOT % NOT Stat ABS ABS ABS ABS ABS ABS Mean1 5.0 5.9 4.1 3.899.5 99.5 Mean2 5.4 6.3 5.7 6.3 97.4 98.2 Locs 9 7 8 2 6 8 Reps 13 8 154 6 12 Diff −0.4 −0.4 −1.6 −2.5 2.1 1.3 Prob 0.331 0.478 0.034 0.3440.205 0.337 ERTLPN LRTLPN % NOT % NOT Stat ABS ABS Mean1 82.1 90.7 Mean284.2 89.5 Locs 9 11 Reps 11 13 Diff −2.1 1.1 Prob 0.789 0.690

[0182] TABLE 2F HYBRID COMPARISON Variety #1: 35D28 Variety #2: 34M94YIELD YIELD MST EGRWTH ESTCNT GDUSHD BU/A 56# BU/A 56# PCT SCORE COUNTGDU Stat ABS % MN % MN % MN % MN % MN Mean1 176.1 102.5 98.5 96.6 103.9102.6 Mean2 172.2 100.0 104.2 89.7 103.0 102.5 Locs 131 131 132 19 8 29Reps 143 143 144 21 12 39 Diff 4.0 2.5 5.7 6.9 0.9 0.1 Prob 0.011 0.0120.000 0.216 0.793 0.770 GDUSLK STKCNT PLTHT EARHT STAGRN ABTSTK GDUCOUNT CM CM SCORE % NOT Stat % MN % MN % MN % MN % MN % MN Mean1 102.9100.5 105.5 108.3 113.7 124.1 Mean2 101.7 100.2 102.9 101.9 112.5 143.6Locs 25 187 23 21 39 3 Reps 34 276 30 24 44 18 Diff 1.2 0.3 2.6 6.4 1.2−19.5 Prob 0.025 0.298 0.019 0.008 0.894 0.109 DRPEAR TSTWT GLFSPTNLFBLT GOSWLT ANTROT % NOT LB/BU SCORE SCORE SCORE SCORE Stat % MN ABSABS ABS ABS ABS Mean1 101.0 55.5 4.4 5.5 7.8 4.3 Mean2 101.0 55.8 6.03.7 7.0 2.7 Locs 1 79 4 11 2 3 Reps 1 83 6 18 4 6 Diff 0.0 −0.3 −1.6 1.70.8 1.7 Prob 0.069 0.007 0.001 0.205 0.038 CLN FUSERS GIBERS DIPERSECBDPE ECB1LF SCORE SCORE SCORE SCORE % NOT SCORE Stat ABS ABS ABS ABSABS ABS Mean1 3.7 5.2 7.8 3.5 97.6 3.7 Mean2 4.0 6.7 8.6 3.0 97.7 3.7Locs 1 7 2 1 6 1 Reps 3 11 3 2 7 3 Diff −0.3 −1.5 −0.8 0.5 −0.1 0.0 Prob0.043 0.720 0.938 ECB2SC HSKCVR GIBROT DIPROT BRTSTK HDSMT SCORE SCORESCORE SCORE % NOT % NOT Stat ABS ABS ABS ABS ABS ABS Mean1 5.0 5.9 4.13.8 99.5 99.8 Mean2 4.9 6.9 5.1 3.5 99.7 93.5 Locs 9 7 8 2 6 6 Reps 13 815 4 6 8 Diff 0.2 −0.9 −1.0 0.3 −0.2 6.3 Prob 0.674 0.015 0.330 0.9100.706 0.010 ERTLPN LRTLPN % NOT % NOT Stat ABS ABS Mean1 82.1 90.7 Mean280.7 76.4 Locs 9 11 Reps 11 13 Diff 1.4 14.3 Prob 0.909 0.046

[0183] TABLE 2G HYBRID COMPARISON Variety #1: 35D28/ Variety #2: 36N70YIELD YIELD MST EGRWTH STKCNT BU/A 56# BU/A 56# PCT SCORE COUNT Stat ABS% MN % MN % MN % MN Mean1 175.8 100.4 104.4 80.9 99.6 Mean2 173.0 99.294.5 80.5 101.3 Locs 178 178 179 2 5 Reps 179 179 180 4 10 Diff 2.8 1.2−9.8 0.4 −1.8 Prob 0.008 0.078 0.000 0.969 0.442 STAGRN TSTWT HSKCVRERTLPN SCORE LB/BU SCORE % NOT Stat % MN ABS ABS ABS Mean1 103.4 55.65.5 80.0 Mean2 120.7 56.7 5.0 59.4 Locs 1 171 1 8 Reps 2 172 2 8 Diff−17.2 −1.1 0.5 20.6 Prob 0.000 0.054

[0184] Further Embodiments of the Invention

[0185] This invention also is directed to methods for producing a maizeplant by crossing a first parent maize plant with a second parent maizeplant wherein either the first or second parent maize plant is PioneerBrand hybrid 35D28. In one embodiment the parent hybrid maize plant35D28 will be crossed with another maize plant, sibbed, or selfed, togenerate an inbred which may be used in the development of additionalplants. In another embodiment, double haploid methods may be used togenerate an inbred plant. Further, this invention is directed to methodsfor producing a hybrid 35D28-progeny maize plant by crossing hybridmaize plant 35D28 with itself or a second maize plant and growing theprogeny seed, and repeating the crossing and growing steps with thehybrid maize 35D28-progeny plant from 1 to 2 times, 1 to 3 times, 1 to 4times, or 1 to 5 times. Thus, any such methods using the hybrid maizeplant 35D28 are part of this invention: selfing, sibbing, backcrosses,hybrid production, crosses to populations, and the like.

[0186] All plants produced using hybrid maize plant 35D28 as a parentare within the scope of this invention, including plants derived fromhybrid maize plant 35D28. Progeny of the breeding methods describedherein may be characterized in any number of ways, such as by traitsretained in the progeny, pedigree and/or molecular markers. Combinationsof these methods of characterization may be used. This includesvarieties essentially derived from variety 35D28 with the term“essentially derived variety” having the meaning ascribed to such termin 7 U.S.C. § 2104(a)(3) of the Plant Variety Protection Act, whichdefinition is hereby incorporated by reference. This also includesprogeny plant and parts thereof with at least one ancestor that ishybrid maize plant 35D28 and more specifically where the pedigree ofthis progeny includes 1, 2, 3, 4, and/or 5 or cross pollinations to amaize plant 35D28, or a plant that has 35D28 as a progenitor. Pedigreeis a method used by breeders of ordinary skill in the art to describethe varieties. Varieties that are more closely related by pedigree arelikely to share common genotypes and combinations of phenotypiccharacteristics. All breeders of ordinary skill in the art maintainpedigree records of their breeding programs. These pedigree recordscontain a detailed description of the breeding process, including alisting of all parental lines used in the breeding process andinformation on how such line was used. Thus, a breeder of ordinary skillin the art would know if 35D28 were used in the development of a progenyline, and would also know how many breeding crosses to a line other than35D28 were made in the development of any progeny line. A progeny lineso developed may then be used in crosses with other, different, maizeinbreds to produce first generation (F₁) maize hybrid seeds and plantswith superior characteristics.

[0187] Specific methods and products produced using hybrid maize plantin plant breeding are encompassed within the scope of the inventionlisted above. One such embodiment is the method of crossing hybrid maizeplant 35D28 with itself to form a homozygous inbred parent line. Hybrid35D28 would be sib or self pollinated to form a population of progenyplants. The population of progeny plants produced by this method is alsoan embodiment of the invention. This first population of progeny plantswill have received all of its alleles from hybrid maize plant 35D28. Theinbreeding process results in homozygous loci being generated and isrepeated until the plant is homozygous at substantially every loci andbecomes an inbred line. Once this is accomplished the inbred line may beused in crosses with other inbred lines, including but not limited toinbred parent lines disclosed herein to generate a first generation ofF1 hybrid plants. One of ordinary skill in the art can utilize breedernotebooks, or molecular methods to identify a particular hybrid plantproduced using an inbred line derived from maize hybrid plant 35D28, inaddition to comparing traits. Any such individual inbred plant is alsoencompassed by this invention.

[0188] These embodiments also include use of these methods withtransgenic or backcross conversions of maize hybrid plant 35D28. Anothersuch embodiment is a method of developing a line genetically similar tohybrid maize plant 35D28 in breeding that involves the repeatedbackcrossing of an inbred parent of, or an inbred line derived from,hybrid maize plant 35D28 to another different maize plant any number oftimes. Using backcrossing methods, or even the tissue culture andtransgenic methods described herein, the backcross conversion methodsdescribed herein, or other breeding methods known to one of ordinaryskill in the art, one can develop individual plants, plant cells, andpopulations of plants that retain at least 25%, 30%, 35%, 40%, 45%, 50%,55%, 60%, 65%, 70%, 75%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%,88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 99.5%genetic similarity or identity to maize hybrid plant 35D28. Thepercentage of the genetics retained in the progeny may be measured byeither pedigree analysis or through the use of genetic techniques suchas molecular markers or electrophoresis. In pedigree analysis, onaverage 50% of the starting germplasm would be passed to the progenyline after one cross to a different line, 25% after another cross to adifferent line, and so on. Molecular markers could also be used toconfirm and/or determine the pedigree of the progeny line. The inbredparent would then be crossed to a second inbred parent of or derivedfrom hybrid maize plant 35D28 to create hybrid maize plant 35D28 withadditional beneficial traits such as transgenes or backcrossconversions.

[0189] One method for producing a line derived from hybrid maize plantis as follows. One of ordinary skill in the art would obtain hybridmaize plant 35D28 and cross it with another variety of maize, such as anelite inbred variety. The F1 seed derived from this cross would be grownto form a population. The nuclear genome of the F1 would be made-up of50% of hybrid maize plant 35D28 and 50% of the other elite variety. TheF1 seed would be grown and allowed to self, thereby forming F2 seed. Onaverage the F2 seed nuclear genome would have derived 50% of its allelesfrom the parent hybrid plant 35D28 and 50% from the other maize variety,but various individual plants from the population would have a muchgreater percentage of their alleles derived from the parent maize hybridplant (Wang J. and R. Bernardo, 2000, Crop Sci. 40:659-665 and Bernardo,R. and A. L. Kahler, 2001, Theor. Appl. Genet 102:986-992). Molecularmarkers of 35D28, or its parents identified from routine screening ofthe deposited samples herein could be used to select and retain thoselines with high similarity to 35D28. The F2 seed would be grown andselection of plants would be made based on visual observation, markersand/or measurement of traits. The traits used for selection may be any35D28 trait described in this specification, including the hybrid maizeplant 35D28 traits of yield, root lodging, drydown, early growth,tolerance to Goss' Wilt, tolerance to Gray Leaf Spot, tolerance toNorthern Leaf Blight, tolerance to Head Smut, tolerance to AnthracnoseStalk Rot, tolerance to Fusarium Ear and Kernel Rot, tolerance toGibberella Ear Rot, extractable grain starch and particularly suited toCanada and to the Central Corn Belt, Northeast, and Eastern areas of theUnited States.

[0190] Such traits may also be the good general or specific combiningability of 35D28, including its ability to produce backcrossconversions, or other hybrids. The 35D28 progeny plants that exhibit oneor more of the desired 35D28 traits, such as those listed above, wouldbe selected and each plant would be harvested separately. This F3 seedfrom each plant would be grown in individual rows and allowed to self.Then selected rows or plants from the rows would be harvestedindividually. The selections would again be based on visual observation,markers and/or measurements for desirable traits of the plants, such asone or more of the desirable 35D28 traits listed above.

[0191] The process of growing and selection would be repeated any numberof times until a 35D28 progeny plant is obtained. The 35D28 progenyinbred plant would contain desirable traits in hybrid combinationderived from hybrid plant 35D28. The resulting progeny line wouldbenefit from the efforts of the inventor(s), and would not have existedbut for the inventor(s) work in creating 35D28. Another embodiment ofthe invention is a 35D28 progeny plant that has received the desirable35D28 traits listed above through the use of 35D28, which traits werenot exhibited by other plants used in the breeding process.

[0192] The previous example can be modified in numerous ways, forinstance selection may or may not occur at every selfing generation, thehybrid may immediately be selfed without crossing to another plant,selection may occur before or after the actual self-pollination processoccurs, or individual selections may be made by harvesting individualears, plants, rows or plots at any point during the breeding processdescribed. In addition, double haploid breeding methods may be used atany step in the process. The population of plants produced at each andany cycle of breeding is also an embodiment of the invention, and onaverage each such population would predictably consist of plantscontaining approximately 50% of its genes from inbred parents of maizehybrid 35D28 in the first breeding cycle, 25% of its genes from inbredparents of maize hybrid 35D28 in the second breeding cycle, 12.5% of itsgenes from inbred parents of maize hybrid 35D28 in the third breedingcycle, 6.25% in the fourth breeding cycle, 3.125% in the fifth breedingcycle, and so on. In each case the use of 35D28 provides a substantialbenefit. The linkage groups of 35D28 would be retained in the progenylines, and since current estimates of the maize genome size is about50,000-80,000 genes (Xiaowu, Gai et al., Nucleic Acids Research, 2000,Vol. 28, No. 1, 94-96), in addition to a large amount of non-coding DNAthat impacts gene expression, it provides a significant advantage to use35D28 as starting material to produce a line that retains desiredgenetics or traits of 35D28.

[0193] Another embodiment of this invention is the method of obtaining asubstantially homozygous 35D28 progeny plant by obtaining a seed fromthe cross of 35D28 and another maize plant and applying double haploidmethods to the F1 seed or F1 plant or to any successive filialgeneration. Such methods substantially decrease the number ofgenerations required to produce an inbred with similar genetics orcharacteristics to 35D28.

[0194] A further embodiment of the invention is a backcross conversionof 35D28 obtained by crossing inbred parent plants of hybrid maize plant35D28, which comprise the backcross conversion. For a dominant oradditive trait at least one of the inbred parents would includebackcross conversion in its genome. For a recessive trait, each parentwould include the backcross conversion in its genome. In each case theresultant hybrid maize plant 35D28 obtained from the cross of theparents includes a backcross conversion or transgene.

[0195] A backcross conversion of 35D28 occurs when DNA sequences areintroduced through traditional (non-transformation) breeding techniques,such as backcrossing (Hallauer et al., 1988), with a parent of 35D28utilized as the recurrent parent. Both naturally occurring andtransgenic DNA sequences may be introduced through backcrossingtechniques. The term backcross conversion is also referred to in the artas a single locus conversion. A backcross conversion may produce a plantwith a trait or locus conversion in at least one or more backcrosses,including at least 2 crosses, at least 3 crosses, at least 4 crosses, atleast 5 crosses and the like. Molecular marker assisted breeding orselection may be utilized to reduce the number of backcrosses necessaryto achieve the backcross conversion. For example, see Openshaw, S. J. etal., Marker-assisted Selection in Backcross Breeding. In: ProceedingsSymposium of the Analysis of Molecular Data, August 1994, Crop ScienceSociety of America, Corvallis, Oreg., where it is demonstrated that abackcross conversion can be made in as few as two backcrosses.

[0196] The complexity of the backcross conversion method depends on thetype of trait being transferred (single genes or closely linked genes asvs. unlinked genes), the level of expression of the trait, the type ofinheritance (cytoplasmic or nuclear) and the types of parents includedin the cross. It is understood by those of ordinary skill in the artthat for single gene traits that are relatively easy to classify, thebackcross method is effective and relatively easy to manage. (SeeHallauer et al. in Corn and Corn Improvement, Sprague and Dudley, ThirdEd. 1998). Desired traits that may be transferred through backcrossconversion include, but are not limited to, waxy starch, sterility(nuclear and cytoplasmic), fertility restoration, grain color (white),nutritional enhancements, drought tolerance, nitrogen utilization,altered fatty acid profile, increased digestibility, low phytate,industrial enhancements, disease resistance (bacterial, fungal orviral), insect resistance, herbicide resistance and yield enhancements.In addition, an introgression site itself, such as an FRT site, Lox siteor other site specific integration site, may be inserted by backcrossingand utilized for direct insertion of one or more genes of interest intoa specific plant variety. The trait of interest is transferred from thedonor parent to the recurrent parent, in this case, an inbred parent ofthe maize plant disclosed herein. In some embodiments of the invention,the number of loci that may be backcrossed into 35D28 is at least 1, 2,3, 4, or 5 and/or no more than 6, 5, 4, 3, or 2. A single loci maycontain several transgenes, such as a transgene for disease resistancethat, in the same expression vector, also contains a transgene forherbicide resistance. The gene for herbicide resistance may be used as aselectable marker and/or as a phenotypic trait. A single locusconversion of site specific integration system allows for theintegration of multiple genes at the converted loci.

[0197] The backcross conversion may result from either the transfer of adominant allele or a recessive allele. Selection of progeny containingthe trait of interest is accomplished by direct selection for a traitassociated with a dominant allele. Transgenes transferred viabackcrossing typically function as a dominant single gene trait and arerelatively easy to classify. Selection of progeny for a trait that istransferred via a recessive allele, such as the waxy starchcharacteristic, requires growing and selfing the first backcrossgeneration to determine which plants carry the recessive alleles.Recessive traits may require additional progeny testing in successivebackcross generations to determine the presence of the locus ofinterest. The last backcross generation is usually selfed to give purebreeding progeny for the gene(s) being transferred, although a backcrossconversion with a stably introgressed trait may also be maintained byfurther backcrossing to the recurrent parent with selection for theconverted trait.

[0198] Along with selection for the trait of interest, progeny areselected for the phenotype of the recurrent parent. While occasionallyadditional polynucleotide sequences or genes may be transferred alongwith the backcross conversion, the backcross conversion line “fits intothe same hybrid combination as the recurrent parent inbred line andcontributes the effect of the additional gene added through thebackcross.” Poehlman et al. (1995, pg. 334). A progeny comprising atleast 95%, 96%, 97%, 98%, 99%, 99.5% and 99.9% genetic identity tohybrid 35D28 and comprising the backcross conversion trait or traits ofinterest, is considered to be a backcross conversion of hybrid 35D28. Ithas been proposed that in general there should be at least fourbackcrosses when it is important that the recovered lines begessentially identical to the recurrent parent except for thecharacteristic being transferred (Fehr 1987, Principles of CultivarDevelopment). However, as noted above, the number of backcrossesnecessary can be reduced with the use of molecular markers. Otherfactors, such as a genetically similar donor parent, may also reduce thenumber of backcrosses necessary.

[0199] Hybrid seed production requires elimination or inactivation ofpollen produced by the female inbred parent. Incomplete removal orinactivation of the pollen provides the potential for self-pollination.A reliable method of controlling male fertility in plants offers theopportunity for improved seed production. It should be understood thatthe plant can, through routine manipulation by detasseling, cytoplasmicgenes, nuclear genes, or other factors, be produced in a male-sterileform. The term manipulated to be male sterile refers to the use of anyavailable techniques to produce a male sterile version of maize line35D28. The male sterility may be either partial or complete malesterility.

[0200] Hybrid maize seed is often produced by a male sterility systemincorporating manual or mechanical detasseling. Alternate strips of twomaize inbreds are planted in a field, and the pollen-bearing tassels areremoved from one of the inbreds (female). Provided that there issufficient isolation from sources of foreign maize pollen, the ears ofthe detasseled inbred will be fertilized only from the other inbred(male), and the resulting seed is therefore hybrid and will form hybridplants.

[0201] Such embodiments are also within the scope of the present claims.This invention includes hybrid maize seed of 35D28 and the hybrid maizeplant produced therefrom. The foregoing was set forth by way of exampleand is not intended to limit the scope of the invention.

[0202] This invention is also directed to the use of hybrid maize plant35D28 in tissue culture. As used herein, the term plant includes plantprotoplasts, plant cell tissue cultures from which maize plants can beregenerated, plant calli, plant clumps, and plant cells that are intactin plants, or parts of plants, such as embryos, pollen, ovules, flowers,kernels, ears, cobs, leaves, seeds, husks, stalks, roots, root tips,anthers, silk and the like. As used herein the phrase “growing the seed”or “grown from the seed” includes embryo rescue, isolation of cells fromseed for use in tissue culture, as well as traditional growing methods.

[0203] Duncan, Williams, Zehr, and Widholm, Planta, (1985) 165:322-332reflects that 97% of the plants cultured which produced callus werecapable of plant regeneration. Subsequent experiments with both inbredsand hybrids produced 91% regenerable callus which produced plants. In afurther study in 1988, Songstad, Duncan & Widholm in Plant Cell Reports(1988), 7:262-265 reports several media additions which enhanceregenerability of callus of two inbred lines. Other published reportsalso indicated that “nontraditional” tissues are capable of producingsomatic embryogenesis and plant regeneration. K. P. Rao, et al., MaizeGenetics Cooperation Newsletter, 60:64-65 (1986), refers to somaticembryogenesis from glume callus cultures and B. V. Conger, et al., PlantCell Reports, 6:345-347 (1987) indicates somatic embryogenesis from thetissue cultures of maize leaf segments. Thus, it is clear from theliterature that the state of the art is such that these methods ofobtaining plants are, and were, “conventional” in the sense that theyare routinely used and have a very high rate of success.

[0204] Tissue culture of maize, including tassel/anther culture, isdescribed in U.S. Application 2002/0062506A1 and European PatentApplication, Publication No. 160,390, each of which are incorporatedherein by reference. Maize tissue culture procedures are also describedin Green and Rhodes, “Plant Regeneration in Tissue Culture of Maize,”Maize for Biological Research (Plant Molecular Biology Association,Charlottesville, Virginia 1982, at 367-372) and in Duncan, et al., “TheProduction of Callus Capable of Plant Regeneration from Immature Embryosof Numerous Zea Mays Genotypes,” 165 Planta 322-332 (1985). Thus,another aspect of this invention is to provide cells which upon growthand differentiation produce maize plants having the genotype and/orphysiological and morphological characteristics of hybrid maize plant35D28.

[0205] The utility of hybrid maize plant 35D28 also extends to crosseswith other species. Commonly, suitable species will be of the familyGraminaceae, and especially of the genera Zea, Tripsacum, Coix,Schlerachne, Polytoca, Chionachne, and Trilobachne, of the tribeMaydeae. Potentially suitable for crosses with 35D28 may be the variousvarieties of grain sorghum, Sorghum bicolor (L.) Moench.

[0206] Transformation of Maize

[0207] The advent of new molecular biological techniques has allowed theisolation and characterization of genetic elements with specificfunctions, such as encoding specific protein products. Scientists in thefield of plant biology developed a strong interest in engineering thegenome of plants to contain and express foreign genetic elements, oradditional, or modified versions of native or endogenous geneticelements in order to alter the traits of a plant in a specific manner.Any DNA sequences, whether from a different species or from the samespecies, that are inserted into the genome using transformation arereferred to herein collectively as “transgenes”. In some embodiments ofthe invention, a transformed variant of 35D28 may contain at least onetransgene but could contain at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10and/or no more than 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, or 2.Over the last fifteen to twenty years several methods for producingtransgenic plants have been developed, and the present invention alsorelates to transformed versions of the claimed hybrid 35D28 as well ascombinations thereof.

[0208] Numerous methods for plant transformation have been developed,including biological and physical plant transformation protocols. See,for example, Miki et al., “Procedures for Introducing Foreign DNA intoPlants” in Methods in Plant Molecular Biology and Biotechnology, Glick,B. R. and Thompson, J. E. Eds. (CRC Press, Inc., Boca Raton, 1993) pp.67-88 and Armstrong, “The First Decade of Maize Transformation: A Reviewand Future Perspective” (Maydica 44:101-109, 1999). In addition,expression vectors and in vitro culture methods for plant cell or tissuetransformation and regeneration of plants are available. See, forexample, Gruber et al., “Vectors for Plant Transformation” in Methods inPlant Molecular Biology and Biotechnology, Glick, B. R. and Thompson, J.E. Eds. (CRC Press, Inc., Boca Raton, 1993) pp. 89-119. See U.S. Pat.No. 6,118,055, which is herein incorporated by reference.

[0209] The most prevalent types of plant transformation involve theconstruction of an expression vector. Such a vector comprises a DNAsequence that contains a gene under the control of or operatively linkedto a regulatory element, for example a promoter. The vector may containone or more genes and one or more regulatory elements.

[0210] A genetic trait which has been engineered into the genome of aparticular maize plant using transformation techniques, could be movedinto the genome of another line using traditional breeding techniquesthat are well known in the plant breeding arts. These lines can then becrossed to generate a hybrid maize plant such as hybrid maize plant35D28 which comprises a transgene. For example, a backcrossing approachis commonly used to move a transgene from a transformed maize plant toan elite inbred line, and the resulting progeny would then comprise thetransgene(s). Also, if an inbred line was used for the transformationthen the transgenic plants could be crossed to a different inbred inorder to produce a transgenic hybrid maize plant. As used herein,“crossing” can refer to a simple X by Y cross, or the process ofbackcrossing, depending on the context.

[0211] Various genetic elements can be introduced into the plant genomeusing transformation. These elements include but are not limited togenes; coding sequences; inducible, constitutive, and tissue specificpromoters; enhancing sequences; and signal and targeting sequences. Forexample, see the traits, genes and transformation methods listed in U.S.Pat. No. 6,284,953, which is herein incorporated by reference.

[0212] With transgenic plants according to the present invention, aforeign protein can be produced in commercial quantities. Thus,techniques for the selection and propagation of transformed plants,which are well understood in the art, yield a plurality of transgenicplants that are harvested in a conventional manner, and a foreignprotein then can be extracted from a tissue of interest or from totalbiomass. Protein extraction from plant biomass can be accomplished byknown methods which are discussed, for example, by Heney and Orr, Anal.Biochem. 114: 92-6 (1981). In one embodiment, the biomass of interest isseed.

[0213] A genetic map can be generated, primarily via conventionalRestriction Fragment Length Polymorphisms (RFLP), Polymerase ChainReaction (PCR) analysis, Simple Sequence Repeats (SSR) and SingleNucleotide Polymorphisms (SNP) which identifies the approximatechromosomal location of the integrated DNA molecule. For exemplarymethodologies in this regard, see Glick and Thompson, METHODS IN PLANTMOLECULAR BIOLOGY AND BIOTECHNOLOGY 269-284 (CRC Press, Boca Raton,1993).

[0214] Wang et al. discuss “Large Scale Identification, Mapping andGenotyping of Single-Nucleotide Polymorphisms in the Human Genome”,Science, 280:1077-1082, 1998, and similar capabilities are becomingincreasingly available for the corn genome. Map information concerningchromosomal location is useful for proprietary protection of a subjecttransgenic plant. If unauthorized propagation is undertaken and crossesmade with other germplasm, the map of the integration region can becompared to similar maps for suspect plants to determine if the latterhave a common parentage with the subject plant. Map comparisons wouldinvolve hybridizations, RFLP, PCR, SSR and sequencing, all of which areconventional techniques. SNPs may also be used alone or in combinationwith other techniques.

[0215] Likewise, by means of the present invention, plants can begenetically engineered to express various phenotypes of agronomicinterest. Through the transformation of maize the expression of genescan be modulated to enhance disease resistance, insect resistance,herbicide resistance, agronomic traits, grain quality and other traits.Transformation can also be used to insert DNA sequences which control orhelp control male-sterility. DNA sequences native to maize as well asnon-native DNA sequences can be transformed into maize and used tomodulate levels of native or non-native proteins. Various promoters,targeting sequences, enhancing sequences, and other DNA sequences can beinserted into the maize genome for the purpose of modulating theexpression of proteins. Reduction of the activity of specific genes(also known as gene silencing, or gene suppression) is desirable forseveral aspects of genetic engineering in plants.

[0216] Many techniques for gene silencing are well known to one of skillin the art, including but not limited to antisense technology (see,e.g., Sheehy et al. (1988) PNAS USA 85:8805-8809; and U.S. Pat. Nos.5,107,065; 5,453,566; and 5,759,829); co-suppression (e.g., Taylor(1997) Plant Cell 9:1245; Jorgensen (1990) Trends Biotech.8(12):340-344; Flavell (1994) PNAS USA 91:3490-3496; Finnegan et al.(1994) Bio/Technology 12: 883-888; and Neuhuber et al. (1994) Mol. Gen.Genet. 244:230-241); RNA interference (Napoli et al. (1990) Plant Cell2:279-289; U.S. Pat. No. 5,034,323; Sharp (1999) Genes Dev. 13:139-141;Zamore et al. (2000) Cell 101:25-33; and Montgomery et al. (1998) PNASUSA 95:15502-15507), virus-induced gene silencing (Burton, et al. (2000)Plant Cell 12:691-705; and Baulcombe (1999) Curr. Op. Plant Bio.2:109-113); target-RNA-specific ribozymes (Haseloff et al. (1988) Nature334: 585-591); hairpin structures (Smith et al. (2000) Nature407:319-320; WO 99/53050; and WO 98/53083); ribozymes (Steinecke et al.((1992) EMBO J. 11:1525; and Perriman et al. ((1993) Antisense Res. Dev.3:253); oligonucleotide mediated targeted modification (e.g., WO03/076574 and WO 99/25853); Zn-finger targeted molecules (e.g., WO01/52620; WO 03/048345; and WO 00/42219); and other methods orcombinations of the above methods known to those of skill in the art.

[0217] Exemplary transgenes useful for genetic engineering include, butare not limited to, those categorized below.

[0218] 1. Transgenes That Confer Resistance To Pests or Disease And ThatEncode:

[0219] (A) Plant disease resistance genes. Plant defenses are oftenactivated by specific interaction between the product of a diseaseresistance gene (R) in the plant and the product of a correspondingavirulence (Avr) gene in the pathogen. A plant variety can betransformed with cloned resistance gene to engineer plants that areresistant to specific pathogen strains. See, for example Jones et al.,Science 266: 789 (1994) (cloning of the tomato Cf-9 gene for resistanceto Cladosporium fulvum); Martin et al., Science 262: 1432 (1993) (tomatoPto gene for resistance to Pseudomonas syndngae pv. tomato encodes aprotein kinase); Mindrinos et al., Cell 78: 1089 (1994) (ArabidopsisRSP2 gene for resistance to Pseudomonas syringae). A plant resistant toa disease is one that is more resistant to a pathogen as compared to thewild type plant.

[0220] (B) A Bacillus thuringiensis protein, a derivative thereof or asynthetic polypeptide modeled thereon. See, for example, Geiser et al.,Gene 48: 109 (1986), who disclose the cloning and nucleotide sequence ofa Bt delta-endotoxin gene. Moreover, DNA molecules encodingdelta-endotoxin genes can be purchased from American Type CultureCollection (Rockville, Md.), for example, under ATCC Accession Nos.40098, 67136, 31995 and 31998. Other examples of Bacillus thuringiensistransgenes being genetically engineered are given in the followingpatents and hereby are incorporated by reference for this purpose: U.S.Pat. Nos. 5,188,960; 5,689,052; 5,880,275; WO 91/114778; WO 99/31248; WO01/12731; WO 99/24581; WO 97/40162 and U.S. patent Ser. Nos. 10/032,717;10/414,637; and 10/606,320.

[0221] (C) An insect-specific hormone or pheromone such as anecdysteroid and juvenile hormone, a variant thereof, a mimetic basedthereon, or an antagonist or agonist thereof. See, for example, thedisclosure by Hammock et al., Nature 344: 458 (1990), of baculovirusexpression of cloned juvenile hormone esterase, an inactivator ofjuvenile hormone.

[0222] (D) An insect-specific peptide or neuropeptide which, uponexpression, disrupts the physiology of the affected pest. For example,see the disclosures of Regan, J. Biol. Chem. 269: 9 (1994) (expressioncloning yields DNA coding for insect diuretic hormone receptor), andPratt et al., Biochem. Biophys. Res. Comm. 163: 1243 (1989) (anallostatin is identified in Diploptera puntata). See also U.S. Pat. No.5,266,317 to Tomalski et al., who disclose genes encodinginsect-specific, paralytic neurotoxins.

[0223] (E) An enzyme responsible for an hyperaccumulation of amonterpene, a sesquiterpene, a steroid, hydroxamic acid, aphenylpropanoid derivative or another non-protein molecule withinsecticidal activity.

[0224] (F) An enzyme involved in the modification, including thepost-translational modification, of a biologically active molecule; forexample, a glycolytic enzyme, a proteolytic enzyme, a lipolytic enzyme,a nuclease, a cyclase, a transaminase, an esterase, a hydrolase, aphosphatase, a kinase, a phosphorylase, a polymerase, an elastase, achitinase and a glucanase, whether natural or synthetic. See PCTApplication WO 93/02197 in the name of Scott et al., which discloses thenucleotide sequence of a callase gene. DNA molecules which containchitinase-encoding sequences can be obtained, for example, from the ATCCunder Accession Nos. 39637 and 67152. See also Kramer et al., InsectBiochem. Molec. Biol. 23: 691 (1993), who teach the nucleotide sequenceof a cDNA encoding tobacco hookworm chitinase, and Kawalleck et al.,Plant Molec. Biol. 21: 673 (1993), who provide the nucleotide sequenceof the parsley ubi4-2 polyubiquitin gene.

[0225] (G) A molecule that stimulates signal transduction. For example,see the disclosure by Botella et al., Plant Molec. Biol. 24: 757 (1994),of nucleotide sequences for mung bean calmodulin cDNA clones, and Griesset al., Plant Physiol. 104: 1467 (1994), who provide the nucleotidesequence of a maize calmodulin cDNA clone.

[0226] (H) A hydrophobic moment peptide. See PCT Application WO 95/16776(disclosure of peptide derivatives of Tachyplesin which inhibit fungalplant pathogens) and PCT Application WO 95/18855 (teaches syntheticantimicrobial peptides that confer disease resistance), the respectivecontents of which are hereby incorporated by reference for this purpose.

[0227] (I) A membrane permease, a channel former or a channel blocker.For example, see the disclosure by Jaynes et al., Plant Sci. 89: 43(1993), of heterologous expression of a cecropin-beta lytic peptideanalog to render transgenic tobacco plants resistant to Pseudomonassolanacearum.

[0228] (J) A viral-invasive protein or a complex toxin derivedtherefrom. For example, the accumulation of viral coat proteins intransformed plant cells imparts resistance to viral infection and/ordisease development effected by the virus from which the coat proteingene is derived, as well as by related viruses. See Beachy et al., Ann.Rev. Phytopathol. 28: 451 (1990). Coat protein-mediated resistance hasbeen conferred upon transformed plants against alfalfa mosaic virus,cucumber mosaic virus, tobacco streak virus, potato virus X, potatovirus Y, tobacco etch virus, tobacco rattle virus and tobacco mosaicvirus. Id.

[0229] (K) An insect-specific antibody or an immunotoxin derivedtherefrom. Thus, an antibody targeted to a critical metabolic functionin the insect gut would inactivate an affected enzyme, killing theinsect. Cf. Taylor et al., Abstract #497, SEVENTH INT'L SYMPOSIUM ONMOLECULAR PLANT-MICROBE INTERACTIONS (Edinburgh, Scotland, 1994)(enzymatic inactivation in transgenic tobacco via production ofsingle-chain antibody fragments).

[0230] (L) A virus-specific antibody. See, for example, Tavladoraki etal., Nature 366: 469 (1993), who show that transgenic plants expressingrecombinant antibody genes are protected from virus attack.

[0231] (M) A developmental-arrestive protein produced in nature by apathogen or a parasite. Thus, fungal endo alpha-1,4-D-polygalacturonasesfacilitate fungal colonization and plant nutrient release bysolubilizing plant cell wall homo-alpha-1,4-D-galacturonase. See Lamb etal., Bio/Technology 10: 1436 (1992). The cloning and characterization ofa gene which encodes a bean endopolygalacturonase-inhibiting protein isdescribed by Toubart et al., Plant J. 2: 367 (1992).

[0232] (N) A developmental-arrestive protein produced in nature by aplant. For example, Logemann et al., Bio/Technology 10: 305 (1992), haveshown that transgenic plants expressing the barley ribosome-inactivatinggene have an increased resistance to fungal disease.

[0233] (O) Genes involved in the Systemic Acquired Resistance (SAR)Response and/or the pathogenesis related genes. Briggs, S., CurrentBiology, 5(2) (1995).

[0234] (P) Antifungal genes (Cornelissen and Melchers, PI. Physiol.101:709-712, (1993) and Parijs et al., Planta 183:258-264, (1991) andBushnell et al., Can. J. of Plant Path. 20(2):137-149 (1998).

[0235] (Q) Detoxification genes, such as for fumonisin, beauvericin,moniliformin and zearalenone and their structurally related derivatives.For example, see U.S. Pat. No. 5,792,931.

[0236] (R) Cystatin and cysteine proteinase inhibitors.

[0237] (S) Defensin genes. See WO 03/000863.

[0238] (T) Genes conferring resistance to nematodes. See WO 03/033651and Urwin et al., Planta 204:472-479 (1998).

[0239] 2. Transgenes That Confer Resistance To A Herbicide, for Example:

[0240] (A) A herbicide that inhibits the growing point or meristem, suchas an imidazolinone or a sulfonylurea. Exemplary genes in this categorycode for mutant ALS and AHAS enzyme as described, for example, by Lee etal., EMBO J. 7: 1241 (1988), and Miki et al., Theor. Appl. Genet. 80:449 (1990), respectively. See also, U.S. Pat. Nos. 5,605,011; 5,013,659;5,141,870; 5,767,361; 5,731,180; 5,304,732; 4,761,373; 5,331,107;5,928,937; and 5,378,824; and international publication WO 96/33270,which are incorporated herein by reference in their entireties for thispurpose.

[0241] (B) Glyphosate. (resistance imparted by mutant5-enolpyruvl-3-phosphikimate synthase (EPSP), and aroA genes,respectively) and other phosphono compounds such as glufosinate(phosphinothricin acetyl transferase (PAT) and Streptomyceshygroscopicus phosphinothricin acetyl transferase (bar) genes), andpyridinoxy or phenoxy proprionic acids and cycloshexones (ACCaseinhibitor-encoding genes). See, for example, U.S. Pat. No. 4,940,835 toShah et al., which discloses the nucleotide sequence of a form of EPSPSwhich can confer glyphosate resistance. U.S. Pat. No. 5,627,061 to Barryet al. also describes genes encoding EPSPS enzymes. See also U.S. Pat.Nos. 6,248,876 B1; 6,040,497; 5,804,425; 5,633,435; 5,145,783;4,971,908; 5,312,910; 5,188,642; 4,940,835; 5,866,775; 6,225,114 B1;6,130,366; 5,310,667; 4,535,060; 4,769,061; 5,633,448; 5,510,471; Re.36,449; RE 37,287 E; and 5,491,288; and international publications WO97/04103; WO 97/04114; WO 00/66746; WO 01/66704; WO 00/66747 and WO00/66748, which are incorporated herein by reference in their entiretiesfor this purpose. Glyphosate resistance is also imparted to plants thatexpress a gene that encodes a glyphosate oxido-reductase enzyme asdescribed more fully in U.S. Pat. Nos. 5,776,760 and 5,463,175, whichare incorporated herein by reference in their entireties for thispurpose. In addition glyphosate resistance can be imparted to plants bythe over expression of genes encoding glyphosate N-acetyltransferase.See, for example, U.S. Application Serial Nos. 60/244,385; 60/377,175and 60/377,719.

[0242] A DNA molecule encoding a mutant aroA gene can be obtained underATCC Accession No. 39256, and the nucleotide sequence of the mutant geneis disclosed in U.S. Pat. No. 4,769,061 to Comai. European PatentApplication No. 0 333 033 to Kumada et al. and U.S. Pat. No. 4,975,374to Goodman et al. disclose nucleotide sequences of glutamine synthetasegenes which confer resistance to herbicides such as L-phosphinothricin.The nucleotide sequence of a phosphinothricin-acetyl-transferase gene isprovided in European Patent No. 0 242 246 and 0 242 236 to Leemans etal. De Greef et al., Bio/Technology 7: 61 (1989), describe theproduction of transgenic plants that express chimeric bar genes codingfor phosphinothricin acetyl transferase activity. See also, U.S. Pat.Nos. 5,969,213; 5,489,520; 5,550,318; 5,874,265; 5,919,675; 5,561,236;5,648,477; 5,646,024; 6,177,616 B1; and 5,879,903, which areincorporated herein by reference in their entireties for this purpose.Exemplary genes conferring resistance to phenoxy proprionic acids andcycloshexones, such as sethoxydim and haloxyfop, are the Acc1-S1,Acc1-S2 and Acc1-S3 genes described by Marshall et al., Theor Appl.Genet. 83: 435 (1992). (C) A herbicide that inhibits photosynthesis,such as a triazine (psbA and gs+ genes) and a benzonitrile (nitrilasegene). Przibilla et al., Plant Cell 3: 169 (1991), describe thetransformation of Chlamydomonas with plasmids encoding mutant psbAgenes. Nucleotide sequences for nitrilase genes are disclosed in U.S.Pat. No. 4,810,648 to Stalker, and DNA molecules containing these genesare available under ATCC Accession Nos. 53435, 67441 and 67442. Cloningand expression of DNA coding for a glutathione S-transferase isdescribed by Hayes et al., Biochem. J. 285: 173 (1992).

[0243] (D) Acetohydroxy acid synthase, which has been found to makeplants that express this enzyme resistant to multiple types ofherbicides, has been introduced into a variety of plants (see, e.g.,Hattori et al. (1995) Mol Gen Genet 246:419). Other genes that confertolerance to herbicides include: a gene encoding a chimeric protein ofrat cytochrome P4507A1 and yeast NADPH-cytochrome P450 oxidoreductase(Shiota et al. (1994) Plant Physiol. 106(1):17-23), genes forglutathione reductase and superoxide dismutase (Aono et al., (1995)Plant Cell Physiol. 36:1687, and genes for various phosphotransferases(Datta et al. (1992) Plant Mol. Biol. 20:619).

[0244] (E) Protoporphyrinogen oxidase (protox) is necessary for theproduction of chlorophyll, which is necessary for all plant survival.The protox enzyme serves as the target for a variety of herbicidalcompounds. These herbicides also inhibit growth of all the differentspecies of plants present, causing their total destruction. Thedevelopment of plants containing altered protox activity which areresistant to these herbicides are described in U.S. Pat. Nos. 6,288,306B1; 6,282,837 B1; and 5,767,373; and international publication WO01/12825, which are incorporated herein by reference in theirentireties.

[0245] 3. Transgenes That Confer Or Contribute To A Grain Trait, SuchAs:

[0246] (A) Modified fatty acid metabolism, for example, by

[0247] (1) Transforming a plant with an antisense gene of stearoyl-ACPdesaturase to increase stearic acid content of the plant. See Knultzonet al., Proc. Natl. Acad. Sci. USA 89: 2624 (1992),

[0248] (2) Elevating oleic acid via FAD-2 gene modification and/ordecreasing linolenic acid via FAD-3 gene modification (see U.S. Pat.Nos. 6,063,947; 6,323,392; and WO 93/11245),

[0249] (3) Altering conjugated linolenic or linoleic acid content, suchas in WO 01/12800,

[0250] (4) Modifying LEC1, AGP, Dekl, Superall, thioredoxin, and/or agamma zein knock out or mutant such as cs27 or TUSC 27. For example, seeWO 02/42424, WO 98/22604, WO 03/011015, U.S. Pat. No. 6,423,886 andRivera-Madrid, R. et. al., Proc. Natl. Acad. Sci. 92:5620-5624 (1995).

[0251] (B) Decreased phytate content, for example, by the

[0252] (1) Introduction of a phytase-encoding gene would enhancebreakdown of phytate, adding more free phosphate to the transformedplant. For example, see Van Hartingsveldt et al., Gene 127: 87 (1993),for a disclosure of the nucleotide sequence of an Aspergillus nigerphytase gene.

[0253] (2) Introduction of a gene that reduces phytate content. Inmaize, this, for example, could be accomplished, by cloning and thenre-introducing DNA associated with one or more of the alleles, such asthe LPA alleles, identified in maize mutants characterized by low levelsof phytic acid, such as in Raboy et al., Maydica 35: 383 (1990) and/orby altering inositol kinase activity as in WO 02/059324, U.S.Application No. 2003/0009011, WO 03/027243, U.S. Application No.2003/0079247 and WO 99/05298.

[0254] (C) Modified carbohydrate composition effected, for example, bytransforming plants with a gene coding for an enzyme that alters thebranching pattern of starch. See Shiroza et al., J. Bacteriol. 170: 810(1988) (nucleotide sequence of Streptococcus mutans fructosyltransferasegene), Steinmetz et al., Mol. Gen. Genet. 200: 220 (1985) (nucleotidesequence of Bacillus subtilis levansucrase gene), Pen et al.,Bio/Technology 10: 292 (1992) (production of transgenic plants thatexpress Bacillus licheniformis alpha-amylase), Elliot et al., PlantMolec. Biol. 21: 515 (1993) (nucleotide sequences of tomato invertasegenes), Søgaard et al., J. Biol. Chem. 268: 22480 (1993) (site-directedmutagenesis of barley alpha-amylase gene), and Fisher et al., PlantPhysiol. 102: 1045 (1993) (maize endosperm starch branching enzyme II).The fatty acid modification genes mentioned above may also be used toeffect starch content and/or composition through the interrelationshipof the starch and oil pathways.

[0255] (D) Altered antioxidant content or composition, such asalteration of tocopherol or tocotrienols. For example, see WO 00/68393involving the manipulation of antioxidant levels through alteration of aphytl prenyl transferase and WO 03/082899 through alteration of ahomogentisate geranyl geranyl transferase.

[0256] (E) Improved digestibility and/or starch extraction throughmodification of UDP-D-xylose 4-epimerase, Fragile 1 and 2, Ref1, HCHL,C4H, such as in WO 99/10498.

[0257] 4. Genes that Control Male-Sterility:

[0258] (A) Introduction of a deacetylase gene under the control of atapetum-specific promoter and with the application of the chemicalN-Ac-PPT (WO 01/29237).

[0259] (B) Introduction of various stamen-specific promoters (WO92/13956, WO 92/13957).

[0260] (C) Introduction of the barnase and the barstar gene (Paul etal., Plant Mol. Biol. 19:611-622, 1992).

[0261] 5. Genes that create a site for site specific DNA integration.This includes the introduction of FRT sites that may be used in theFLP/FRT system and/or Lox sites that may be used in the Cre/Loxp system.For example, see Lyznik, et al., Site-Specific Recombination for GeneticEngineering in Plants, Plant Cell Rep (2003) 21:925-932 which is herebyincorporated by reference. Other systems that may be used include theGin recombinase of phage Mu (Maeser et al., 1991), the Pin recombinaseof E. coli (Enomoto et al., 1983), and the R/RS system of the pSR1plasmid (Araki et al., 1992).

[0262] 6. Genes that affect growth characteristics, such as droughttolerance and nitrogen utilization. For example, see WO 00/73475 wherewater use efficiency is modulated through alteration of malate.

[0263] Genetic Marker Profile Through SSR

[0264] The present invention comprises a hybrid corn plant which ischaracterized by the molecular and physiological data presented hereinand in the representative sample of said hybrid and of the inbredparents of said hybrid deposited with the ATCC.

[0265] To select and develop a superior hybrid, it is necessary toidentify and select genetically unique individuals that occur in asegregating population. The segregating population is the result of acombination of crossover events plus the independent assortment ofspecific combinations of alleles at many gene loci that results inspecific and unique genotypes. Once such a line is developed its valueto society is substantial since it is important to advance the germplasmbase as a whole in order to maintain or improve traits such as yield,disease resistance, pest resistance and plant performance in extremeweather conditions. Backcross trait conversions are routinely used toadd or modify one or a few traits of such a line and this furtherenhances its value and usefulness to society. The genetic variationamong individual progeny of a breeding cross allows for theidentification of rare and valuable new genotypes. Once identified, itis possible to utilize routine and predictable breeding methods todevelop progeny that retain the rare and valuable new genotypesdeveloped by the initial breeder.

[0266] Phenotypic traits exhibited by 35D28 can be used to characterizethe genetic contribution of 35D28 to progeny lines developed through theuse of 35D28. Quantitative traits including, but not limited to, yield,maturity, stay green, root lodging, stalk lodging, and early growth aretypically governed by multiple genes at multiple loci. 35D28 progenyplants that retain the same degree of phenotypic expression of thesequantitative traits as 35D28 have received significant genotypic andphenotypic contribution from 35D28. This characterization is enhancedwhen such quantitative trait is not exhibited in non-35D28 breedingmaterial used to develop the 35D28 progeny.

[0267] As discussed, supra, in addition to phenotypic observations, aplant can also be described by its genotype. The genotype of a plant canbe described through a genetic marker profile which can identify plantsof the same variety, a related variety or be used to determine orvalidate a pedigree. Genetic marker profiles can be obtained) bytechniques such as Restriction Fragment Length Polymorphisms (RFLPs),Randomly Amplified Polymorphic DNAs (RAPDs), Arbitrarily PrimedPolymerase Chain Reaction (AP-PCR), DNA Amplification Fingerprinting(DAF), Sequence Characterized Amplified Regions (SCARs), AmplifiedFragment Length Polymorphisms (AFLPs), Simple Sequence Repeats (SSRs)which are also referred to as Microsatellites, and Single NucleotidePolymorphisms (SNPs). For example, see Berry, Don, et al., “AssessingProbability of Ancestry Using Simple Sequence Repeat Profiles:Applications to Maize Hybrids and Inbreds”, Genetics, 2002, 161:813-824,which is incorporated by reference herein in its entirety.

[0268] Particular markers used for these purposes are not limited to theset of markers disclosed herewithin, but are envisioned to include anytype of marker and marker profile which provides a means ofdistinguishing varieties. In addition to being used for identificationof inbred parents, hybrid variety 35D28, a hybrid produced through theuse of 35D28 or its parents, and the identification or verification ofpedigree for progeny plants produced through the use of 35D28, thegenetic marker profile is also useful in breeding and developingbackcross conversions.

[0269] Means of performing genetic marker profiles using SSRpolymorphisms are well known in the art. SSRs are genetic markers basedon polymorphisms in repeated nucleotide sequences, such asmicrosatellites. A marker system based on SSRs can be highly informativein linkage analysis relative to other marker systems in that multiplealleles may be present. Another advantage of this type of marker isthat, through use of flanking primers, detection of SSRs can beachieved, for example, by the polymerase chain reaction (PCR), therebyeliminating the need for labor-intensive Southern hybridization. ThePCR™ detection is done by use of two oligonucleotide primers flankingthe polymorphic segment of repetitive DNA. Repeated cycles of heatdenaturation of the DNA followed by annealing of the primers to theircomplementary sequences at low temperatures, and extension of theannealed primers with DNA polymerase, comprise the major part of themethodology.

[0270] Following amplification, markers can be scored by gelelectrophoresis of the amplification products. Scoring of markergenotype is based on the size of the amplified fragment as measured bymolecular weight (MW) rounded to the nearest integer. While variation inthe primer used or in laboratory procedures can affect the reportedmolecular weight, relative values should remain constant regardless ofthe specific primer or laboratory used. When comparing lines it ispreferable if all SSR profiles are performed in the same lab. An SSRservice is available to the public on a contractual basis by DNALandmarks in Saint-Jean-sur-Richelieu, Quebec, Canada (formerly Paragen,Celera AgGen, Perkin-Elmer AgGen, Linkage Genetics and NPI).

[0271] Primers used for the SSRs suggested herein are publicly availableand may be found in the Maize GDB using the World Wide Web prefixfollowed by maizegdb.org (maintained by the USDA Agricultural ResearchService), in Sharopova et al. (Plant Mol. Biol. 48(5-6):463-481), Lee etal. (Plant Mol. Biol. 48(5-6); 453-461). Primers may be constructed frompublicly available sequence information. Some marker information may beavailable from DNA Landmarks.

[0272] A genetic marker profile of a hybrid should be the sum of itsinbred parents, e.g., if one inbred parent is homozygous for allele x ata particular locus, and the other inbred parent is homozygous for alleley at that locus, the F1 hybrid will be x.y (heterozygous) at that locus.The profile can therefore be used to identify the inbred parents ofhybrid 35D28. The determination of the male set of alleles and thefemale set of alleles may be made by profiling the hybrid and thepericarp of the hybrid seed, which is composed of maternal parent cells.The paternal parent profile is obtained by subtracting the pericarpprofile from the hybrid profile.

[0273] In addition, plants and plant parts substantially benefiting fromthe use of 35D28 in their development such as 35D28 comprising abackcross conversion, transgene, or genetic sterility factor, may beidentified by having a molecular marker profile with a high percentidentity to 35D28. Such a percent identity might be 95%, 96%, 97%, 98%,99%, 99.5% or 99.9% identical to 35D28.

[0274] The SSR profile of 35D28 also can be used to identify essentiallyderived varieties and other progeny lines developed from the use of35D28, as well as cells and other plant parts thereof. Progeny plantsand plant parts produced using 35D28 may be identified by having amolecular marker profile of at least 25%, 30%, 35%, 40%, 45%, 50%, 55%,60%, 65%, 70%, 75%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%,89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 99.5% geneticcontribution from hybrid maize plant 35D28.

[0275] Recurrent Selection and Mass Selection

[0276] Recurrent selection is a method used in a plant breeding programto improve a population of plants. 35D28 is suitable for use in arecurrent selection program. The method entails individual plants crosspollinating with each other to form progeny. The progeny are grown andthe superior progeny selected by any number of selection methods, whichinclude individual plant, half-sib progeny, full-sib progeny, selfedprogeny and topcrossing. The selected progeny are cross pollinated witheach other to form progeny for another population. This population isplanted and again superior plants are selected to cross pollinate witheach other. Recurrent selection is a cyclical process and therefore canbe repeated as many times as desired. The objective of recurrentselection is to improve the traits of a population. The improvedpopulation can then be used as a source of breeding material to obtaininbred lines to be used in hybrids or used as parents for a syntheticcultivar. A synthetic cultivar is the resultant progeny formed by theintercrossing of several selected inbreds.

[0277] Mass selection is a useful technique when used in conjunctionwith molecular marker enhanced selection. In mass selection seeds fromindividuals are selected based on phenotype and/or genotype. Theseselected seeds are then bulked and used to grow the next generation.Bulk selection requires growing a population of plants in a bulk plot,allowing the plants to self-pollinate, harvesting the seed in bulk andthen using a sample of the seed harvested in bulk to plant the nextgeneration. Instead of self pollination, directed pollination could beused as part of the breeding program.

[0278] Mutation Breeding

[0279] Mutation breeding is one of many methods that could be used tointroduce new traits into 35D28. Mutations that occur spontaneously orare artificially induced can be useful sources of variability for aplant breeder. The goal of artificial mutagenesis is to increase therate of mutation for a desired characteristic. Mutation rates can beincreased by many different means including temperature, long-term seedstorage, tissue culture conditions, radiation; such as X-rays, Gammarays (e.g. cobalt 60 or cesium 137), neutrons, (product of nuclearfission by uranium 235 in an atomic reactor), Beta radiation (emittedfrom radioisotopes such as phosphorus 32 or carbon 14), or ultravioletradiation (preferably from 2500 to 2900 nm), or chemical mutagens (suchas base analogues (5-bromo-uracil), related compounds (8-ethoxycaffeine), antibiotics (streptonigrin), alkylating agents (sulfurmustards, nitrogen mustards, epoxides, ethylenamines, sulfates,sulfonates, sulfones, lactones), azide, hydroxylamine, nitrous acid, oracridines. Once a desired trait is observed through mutagenesis thetrait may then be incorporated into existing germplasm by traditionalbreeding techniques, such as backcrossing. Details of mutation breedingcan be found in “Principals of Cultivar Development” Fehr, 1993Macmillan Publishing Company the disclosure of which is incorporatedherein by reference. In addition, mutations created in other lines maybe used to produce a backcross conversion of 35D28 that comprises suchmutation.

INDUSTRIAL APPLICABILITY

[0280] Maize is used as human food, livestock feed, and as raw materialin industry. The food uses of maize, in addition to human consumption ofmaize kernels, include both products of dry- and wet-milling industries.The principal products of maize dry milling are grits, meal and flour.The maize wet-milling industry can provide maize starch, maize syrups,and dextrose for food use. Maize oil is recovered from maize germ, whichis a by-product of both dry- and wet-milling industries.

[0281] Maize, including both grain and non-grain portions of the plant,is also used extensively as livestock feed, primarily for beef cattle,dairy cattle, hogs, and poultry.

[0282] Industrial usds of maize include production of ethanol, maizestarch in the wet-milling industry and maize flour in the dry-millingindustry. The industrial applications of maize starch and flour arebased on functional properties, such as viscosity, film formation,adhesive properties, and ability to suspend particles. The maize starchand flour have application in the paper and textile industries. Otherindustrial uses include applications in adhesives, building materials,foundry binders, laundry starches, explosives, oil-well muds, and othermining applications.

[0283] Plant parts other than the grain of maize are also used inindustry: for example, stalks and husks are made into paper andwallboard and cobs are used for fuel and to make charcoal.

[0284] The seed of the hybrid maize plant, the plant produced from theseed, a plant produced from crossing of maize hybrid plant 35D28 andvarious parts of the hybrid maize plant and transgenic versions of theforegoing, can be utilized for human food, livestock feed, and as a rawmaterial in industry.

DEPOSITS

[0285] Applicant has made a deposit of at least 2500 seeds of hybridmaize 35D28 with the American Type Culture Collection (ATCC), Manassas,Va. 20110 USA, ATCC Deposit No. ______. The seeds deposited with theATCC on ______ were taken from the deposit maintained by Pioneer Hi-BredInternational, Inc., 800 Capital Square, 400 Locust Street, Des Moines,Iowa 50309-2340 since prior to the filing date of this application.Access to this deposit will be available during the pendency of theapplication to the Commissioner of Patents and Trademarks and personsdetermined by the Commissioner to be entitled thereto upon request. Uponallowance of any claims in the application, the Applicant will makeavailable to the public, pursuant to 37 C.F.R. § 1.808, sample(s) of thedeposit of at least 2500 seeds of hybrid maize 35D28 with the AmericanType Culture Collection (ATCC), 10801 University Boulevard, Manassas,Va. 20110-2209. This deposit of seed of hybrid maize 35D28 will bemaintained in the ATCC depository, which is a public depository, for aperiod of 30 years, or 5 years after the most recent request, or for theenforceable life of the patent, whichever is longer, and will bereplaced if it becomes nonviable during that period. Additionally,Applicant has satisfied all the requirements of 37 C.F.R. §§1.801-1.809,including providing an indication of the viability of the sample upondeposit. Applicant has no authority to waive any restrictions imposed bylaw on the transfer of biological material or its transportation incommerce. Applicant does not waive any infringement of their rightsgranted under this patent or under the Plant Variety Protection Act (7USC 2321 et seq.). U.S. Plant Variety Protection of Hybrid Maize 35D28has been applied for under Application No. ______.

[0286] All publications, patents and patent applications mentioned inthe specification are indicative of the level of those skilled in theart to which this invention pertains. All such publications, patents andpatent applications are incorporated by reference herein to the sameextent as if each was specifically and individually indicated to beincorporated by reference herein.

[0287] The foregoing invention has been described in detail by way ofillustration and example for purposes of clarity and understanding.However, it will be obvious that certain changes and modifications suchas backcross conversions and mutations, somoclonal variants, variantindividuals selected from large populations of the plants of the instantinbred and the like may be practiced within the scope of the invention,as limited only by the scope of the appended claims.

What is claimed is:
 1. Seed of hybrid maize variety designated 35D28,representative seed of said variety having been deposited under ATCCAccession Number ______.
 2. A maize plant, or a part thereof, producedby growing the seed of claim
 1. 3. Pollen of the plant of claim
 2. 4. Anovule of the plant of claim
 2. 5. A tissue culture of regenerable cellsproduced from the plant of claim
 2. 6. Protoplasts produced from thetissue culture of claim
 5. 7. The tissue culture of claim 5, whereincells of the tissue culture are from a tissue selected from the groupconsisting of leaf, pollen, embryo, root, root tip, anther, silk,flower, kernel, ear, cob, husk and stalk.
 8. A maize plant regeneratedfrom the tissue culture of claim 5, said plant having all themorphological and physiological characteristics of hybrid maize plant35D28, representative seed of said plant having been deposited underATCC Accession No. ______.
 9. A method for producing an F1 hybrid maizeseed, comprising crossing the plant of claim 2 with a different maizeplant and harvesting the resultant F1 hybrid maize seed.
 10. A maizeplant, or a part thereof, having all the physiological and morphologicalcharacteristics of the hybrid maize plant 35D28, representative seed ofsaid plant having been deposited under ATCC Accession No. ______.
 11. Amethod of introducing a desired trait into a hybrid maize variety 35D28comprising: (a) crossing at least one of inbred maize parent plantsGE568076 and GE760370, representative seed of which have been depositedunder ATCC Accession Nos. as ______ and ______ respectively, withanother maize line that comprises a desired trait, to produce F1 progenyplants, wherein the desired trait is selected from the group consistingof male sterility, herbicide resistance, insect resistance, diseaseresistance and waxy starch; (b) selecting said F1 progeny plants thathave the desired trait to produce selected F1 progeny plants; (c)backcrossing the selected progeny plants with said inbred maize parentplant to produce backcross progeny plants; (d) selecting for backcrossprogeny plants that have the desired trait and morphological andphysiological characteristics of said inbred maize parent plant toproduce selected backcross progeny plants; (e) repeating steps (c) and(d) three or more times in succession to produce a selected fourth orhigher backcross progeny plants; and (f) crossing said fourth or higherbackcross progeny plant with the other inbred maize parent plant toproduce a hybrid maize variety 35D28 with the desired trait and all ofthe morphological and physiological characteristics of hybrid maizevariety 35D28 listed in Table 1 as determined at the 5% significancelevel when grown in the same environmental conditions.
 12. A plantproduced by the method of claim 11, wherein the plant has the desiredtrait and all of the physiological and morphological characteristics ofhybrid maize variety 35D28 listed in Table 1 as determined at the 5%significance level when grown in the same environmental conditions. 13.The plant of claim 12 wherein the desired trait is herbicide resistanceand the resistance is conferred to an herbicide selected from the groupconsisting of: imidazolinone, sulfonylurea, glyphosate, glufosinate,L-phosphinothricin, triazine and benzonitrile.
 14. The plant of claim 12wherein the desired trait is insect resistance and the insect resistanceis conferred by a transgene encoding a Bacillus thuringiensis endotoxin.15. The plant of claim 12 wherein the desired trait is male sterilityand the trait is conferred by a cytoplasmic nucleic acid molecule thatconfers male sterility.
 16. A method of modifying fatty acid metabolism,phytic acid metabolism or carbohydrate metabolism in a hybrid maizevariety 35D28 comprising: (a) crossing at least one of inbred maizeparent plants GE568076 and GE760370, representative seed of which havebeen deposited under ATCC Accession Nos. as ______ and ______respectively, with another maize line that comprises a nucleic acidmolecule encoding an enzyme selected from the group consisting ofphytase, stearyl-ACP desaturase, fructosyltransferase, levansucrase,alpha-amylase, invertase and starch branching enzyme; (b) selecting saidF1 progeny plants that have said nucleic acid molecule to produceselected F1 progeny plants; (c) backcrossing the selected progeny plantswith said inbred maize parent plant to produce backcross progeny plants;(d) selecting for backcross progeny plants that have said nucleic acidmolecule and morphological and physiological characteristics of saidinbred maize parent plant to produce selected backcross progeny plants;(e) repeating steps (c) and (d) three or more times in succession toproduce a selected fourth or higher backcross progeny plants; and (f)crossing said fourth or higher backcross progeny plant with the otherinbred maize parent plant to produce a hybrid maize variety 35D28 thatcomprises said nucleic acid molecule and has all of the morphologicaland physiological characteristics of hybrid maize variety 35D28 listedin Table 1 as determined at the 5% significance level when grown in thesame environmental conditions.
 17. A plant produced by the method ofclaim 16, wherein the plant comprises the nucleic acid molecule and hasall of the physiological and morphological characteristics of hybridmaize variety 35D28 listed in Table 1 as determined at the 5%significance level when grown in the same environmental conditions. 18.A method for producing a maize seed, comprising crossing the plant ofclaim 2 with itself or a different maize plant and harvesting theresultant maize seed.